tools for teaching crystallography
A mixed phosphine sulfide/selenide structure as an instructional example for how to evaluate the quality of a model
aDepartment of Chemistry, University of Kentucky, Lexington, KY, 40506, USA, bDepartment of Chemistry, Grand Valley State University, Allendale, MI 49401, USA, and cCenter for Crystallographic Research, Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
*Correspondence e-mail: s.parkin@uky.edu, biross@gvsu.edu
This paper compares variations on a structure model derived from an X-ray diffraction data set from a cis-1,2-bis(diphenylphosphanyl)ethylene, namely, 1,2-(ethene-1,2-diyl)bis(diphenylphoshpine sulfide/selenide), C26H22P2S1.13Se0.87. A sequence of processes are presented to ascertain the composition of the crystal, along with strategies for which aspects of the model to inspect to ensure a chemically and crystallographically realistic structure. Criteria include mis-matches between Fobs2 and Fcalc2, plots of |Fobs| vs |Fcalc|, residual electron density, checkCIF alerts, pitfalls of the OMIT command used to suppress ill-fitting data, comparative size of displacement ellipsoids, and critical inspection of interatomic distances. Since the structure is quite small, solves easily, and presents a number of readily expressible concepts, we feel that it would make a straightforward and concise instructional piece for students learning how to determine if their model provides the best fit for the data and show students how to critically assess their structures.
of chalcogenide derivatives ofKeywords: checkCIF alerts; F2obs vs F2calc; OMIT command; outliers; displacement ellipsoids; solid solution; disordered electron density; standard interatomic distances; crystal structure.
CCDC reference: 2231833
1. Chemical context
Our research group has synthesized a number of phosphine chalogenide derivatives and explored their chemistry in regard to their coordination with both d-block and f-block metals (Luster et al., 2022; Mugemana et al., 2018; Morse et al., 2016; Neils et al., 2022). A few years ago, we worked with the rigid diphosphine cis-1,2-bis(diphenylphosphine)ethylene 1 (cis-dppe), and developed conditions for the synthesis of the di-sulfide 2 (Rawls et al., 2023) and the di-selenide 3 (Jones et al., 2015) (Fig. 1). We obtained X-ray diffraction data for both 2 and 3, and the structures were isomorphic, having the symmetry of the orthorhombic P212121. Our synthetic efforts then turned to preparation of mono-selenide 4 as a way to gain access to the mixed sulfide-selenide system, 5.
2. Structure solution and model building trials
We obtained diffraction data for crystals grown directly from the reaction mixture. The structure solved easily in P212121 using SHELXT (Sheldrick, 2015a) with included scattering factors for C, H, P, Se and a that was clearly related to those of compounds 2 and 3. In the initial solution, however, SHELXT had assigned scattering factors for phosphorus to both chalcogen sites, a chemical impossibility. In terms of similarity of scattering factors, sulfur would be the obvious next choice for the chalcogen, but the pnictogen-to-chalcogen distances (vide infra) were much longer than in the di-sulfide structure 2 (Rawls et al., 2023). Given the available electron density at the chalcogen site, a disordered mono-selenide model seemed plausible. Of paramount importance here is that any trial model must be chemically plausible, thus knowledge of chemistry and information from other spectroscopic techniques (if available) should be used to rule out alternatives.
2.1. Trial 1: a mono-selenide model
Manual editing of the chalcogen sites to accommodate a single Se atom split over the two sites gave a model that refined smoothly using SHELXL (Sheldrick, 2015b), giving a disordered Se occupancy ratio of 0.526 (2):0.474 (2) (Fig. 2a). The P=Se distances were 2.063 (2) and 2.035 (2) Å, and the model converged to an R1 value of 0.0494.
This model passed all the typical checkCIF tests, apart from returning a B-level alert indicating the presence of a few reflections with a poor fit between Fobs2 and Fcalc2. The SHELXL list of `most disagreeable reflections' (i.e, mis-matches between observed and calculated data) showed a striking difference for four reflections (Table 1, Fig. 2b). At this point, it might be tempting to simply remove the top few poorly fitting reflections (i.e., those having error/s.u. > 10) using the OMIT command in SHELXL and be satisfied with the structure. However, all of the worst outliers (see Table 1) have Fobs2 >> Fcalc2 and are at resolutions far removed from the beamstop shadow. Thus, the commonly blamed culprit of `obscured by the beamstop' would not provide any justification for omission. Unfortunately, uncritical omission of the worst-offending reflections in order to suppress unfavourable checkCIF alerts has become all too common. When Fobs2 >> Fcalc2, however, such ill-fitting intensities are precisely the datapoints that are most sensitive to any model deficiencies. Modern data-reduction software includes facilities to identify the particular frame for any such outliers for manual inspection. In the present case, the offending reflections appeared to have been measured properly; no justification for omission was apparent. A closer look at the model showed that the displacement ellipsoids for the Se atoms were a little on the small side relative to neighbouring atoms, and that the residual difference-Fourier map showed pronounced electron density with several small embedded difference-map peaks (each less than 0.9 e Å−3) clustered near the chalcogen sites (Fig. 2c). These `features' suggest that this model did not fully account for all the electron density present in the data.
2.2. Trial 2: a di-selenide model
To better account for the residual electron density, we built a model that corresponded to the di-selenide 3, in which each Se atom had a fixed occupancy of 1.0 (Table 2 and Fig. 3). The resulting P=Se distances were (unsurprisingly) similar to those for the previous model at 2.061 (2) and 2.030 (2) Å. However, the R1 value for this model jumped to 0.0632 and the mis-match between the values of the displacement parameter tensors for the Se atoms and those for the rest of the atoms in the structure became wholly unrealistic (Fig. 3a). Moreover, the discrepancy between the top four `disagreeable' reflections became even larger, and the |Fobs| vs |Fcalc| plot was a little more scattered (Fig. 3b). By any measure, the di-selenide model is demonstrably worse than the mono-selenide model. Comparison of these two models, however, suggests that the electron density for the chalcogen atom sites present in the crystal that produced the diffraction data was insufficient to support two fully occupied selenium atoms, but it was too much for a mono-selenide model.
|
2.3. Trial 3: a mono-selenide/di-selenide solid-solution model
Since atomic scattering factors are (to a first approximation) proportional to a). The R1 value dropped quite precipitously to 0.0236 and the displacement ellipsoids for all atoms appeared to be acceptable. For this model, the checkCIF report revealed no B-level alerts, and the discrepancy between the top four observed vs calculated mis-matches was correspondingly much smaller than for any of the previous models (Table 3 and Fig. 4b).
of the occupancies at the chalcogen sites should give a good estimate of the amount of available density. Thus, to better fit the available electron density, the occupancies at each Se atom were refined freely, which gave occupancies of 0.712 (2) and 0.655 (2) for the two chalcogen sites (Fig. 42.4. Trial 4: a mixed selenide/sulfide solid-solution model
At this point, the statistics for the model were acceptable and checkCIF raised no red flags. Nonetheless, a critical comparison of the P=Se distances in the model shown in Fig. 4a to values listed in International Tables for Crystallography vol. C (Table 9.5.1.1; Prince, 2006) and updated information in the CSD (Groom et al., 2016) available via MOGUL (Bruno et al., 2004) revealed additional chemical evidence that the outwardly acceptable model was subtly flawed. The average length for P=Se bonds is listed in these resources as 2.093 Å, while that of P=S bonds is 1.954 Å. The lengths of the P=Se bonds in the model shown in Fig. 4a are in between these two values at 2.060 (8) and 2.0328 (8) Å. This observation is reminiscent of work by Gerard Parkin and co-workers in de-bunking the bond-stretch theory (Parkin, 1992), in which improbable `bond lengths' were shown to result from undiagnosed chemical inhomogeneity rather than unrealistic bond-length differences.
In a similar vein, one logical explanation for the discrepancy in the present case was that the sample could have been contaminated with some di-sulfide 2. These compounds were all synthesized several years ago, and the mixed Se/S compound had been one of the synthetic goals (vide supra). Modification of the model to include selenium and sulfur at both sites, where the occupancies of these atoms were refined to sum to unity, resulted in the model shown in Fig. 5a and 6. This model has an R1 value of 0.0209, notably lower than the previous selenide-only model, with the relative sulfur-to-selenium occupancies for each site being 0.513 (3):0.487 (3) and 0.614 (3):0.386 (3). The bond lengths for this final model are also in reasonable agreement with literature averages, the P=Se distances being 2.082 (8) and 2.088 (11) Å, while the P=S distances are 2.021 (19) and 1.953 (16) Å, directly from i.e., without distance restraints. Since the literature P=S distance is only ∼0.934 that of P=Se (i.e., 1.954/2.093 vide supra), had the relative sulfur occupancy been much lower, then a restraint to tie the P=Se/S distances via an FVAR parameter in SHELXL might have been necessary. A look at the list of `disagreeable' reflections also shows an improvement (Tables 1–4). Note in particular that none of the worst offenders in Table 1 or 2 show up in Table 4. Based on these features and statistics, the structure for 5 shown in Fig. 6 is demonstrably the superior model for this crystal.
3. Structural commentary
The structure of 5 (Fig. 6) shares many similarities with the di-sulfide 2 (structure I in Rawls et al., 2023) and the di-selenide 3 (Jones et al., 2015). As stated in section 2.4, in spite of the superpositional disorder of Se and S at both chalcogen sites, the unrestrained pnictogen-to-chalcogen bond distances [P1=Se1 = 2.0818 (8), P2=Se2 = 2.0879 (11), P1=S1 = 2.021 (19), P2=S2 = 1.953 (16) Å] are within or close to the normal ranges. All other bond distances and angles are also normal. There is a slight twist out of planarity at C1=C2, which gives a P1—C1—C2—P2 torsion angle of 9.0 (5)°. This, and torsion angles C9—P1—C1—C2 [−35.3 (3)°] and C1—C2—P2—C21 [−34. (3)°] effectively place phenyl rings C9–C14 and C12–C26 into an intramolecular π–π-stacking arrangement. The dihedral angle between these overlapped phenyl rings is only 5.45 (3)° although the stacking is skewed, leading to a ring centroid–centroid distance of 3.737 (4) Å.
4. Supramolecular features
The molecular packing in 5 is similar to that in the di-sulfide 2 (Rawls et al., 2023) and the di-selenide 3 (Jones et al., 2015). Since all hydrogen atoms are bound to carbon, there are no strong hydrogen bonds. There are also no intermolecular π–π interactions, though there are numerous weak C—H⋯π contacts. A Hirshfeld-surface analysis mapped over dnorm (Fig. 7) shows that intermolecular contacts are dominated by hydrogen, either to other hydrogen atoms (55.0% of contacts), or to carbon (24.6%), or Se/S sites (16.4%). The remainder of the contacts (C⋯C at 3.3% and C⋯Se/S at 0.7%) are negligible. The strongest interactions, however, i.e. those in which distances are appreciably less than the sum of van der Waals radii (see intense red spots in Fig. 7a) are from C—H⋯Se/S contacts (Table 5).
|
5. Database survey
The Cambridge Structural Database (CSD, v5.43 with all updates through Nov. 2022; Groom et al., 2016) returns 5727 entries for a search fragment consisting of the dppe molecule. Of these, 895 have `any atom' single bonded to the phosphorus and 267 are double bonded. There are 35 entries with two P=S bonds and 17 with two P=Se bonds. There are also some mixed species; 33 entries have just one P=S and two entries have just one P=Se, though these mixed structures have little else in common with structure 5 discussed herein. The closest structures to 5 are the di-selenide structures YOWTIP (Jones et al., 2015) and the di-sulfide CAMCUR01 (Rawls et al., 2023).
6. Refinement
A summary of data collection details and structure . Hydrogen atoms were found in difference-Fourier maps, but subsequently included in the using riding models, with constrained distances set to 0.95 Å. Uiso(H) values were set to 1.2Ueq of the attached carbon atom. To ensure satisfactory constraints (SHELXL command EADP) were used to equalize displacement parameters of superimposed Se/S atoms.
is given in Table 6
|
7. Conclusions
This Fobs2 and Fcalc2 mis-matches, plots of |Fobs| vs |Fcalc| and comparison of interatomic distances to literature averages. Of particular importance is that the analysis highlights the dangers of uncritical suppression of outliers by inappropriate use of the OMIT command in SHELXL. Since the path to determining the best model inevitably varies from one structure to the next, a few additional points to consider, along with some background and, where appropriate, strategies to deal with them are included in the supporting information.
can serve as a straightforward instructional tool to demonstrate the varied pieces of information used to determine the quality and ultimately the correctness of a model. Here we investigated residual electron density, size of displacement ellipsoids,8. Related literature
The supporting information includes a number of references that are not cited in the main paper. These sources are not exhaustive, but might serve as a useful starting point for further enquiry by an interested student. They are grouped by their respective contexts and cited here:
General advice on structure and refinement strategy: Watkin, 1994; Clegg, 2019; Linden, 2020; Spek, 2020.
Twinning: Hahn & Klapper, 2006; Donnay & Donnay, 1959; Nespolo & Ferraris, 2003; Nespolo, 2015, 2019; Nespolo et al., 2020; Herbst-Irmer & Sheldrick, 1998, 2002; Parsons, 2003; Parkin, 2021; Spek, 2020; Cooper et al., 2002.
Molecular geometry and crystal symmetry: Parkin, 1992; Allen et al., 1987; Orpen et al., 1989; Prince, 2006; Baur & Kassner, 1992; Marsh, 1997; Marsh & Spek, 2001; Le Page, 1987, 1988; Mohamed et al. (2016); Parkin et al., 2023; Vinaya et al. (2023); Artioli et al. (1997); Parkin & Hope (1998).
Rigid-body motion and TLS analysis: Schomaker & Trueblood, 1968; Haestier et al., 2008.
Absorption correction: de Meulenaer & Tompa, 1965; Blessing, 1995; Krause et al., 2015.
Extinction correction: Darwin, 1914a,b; Becker & Coppens, 1974; Larson, 1967.
SQUEEZE: van der Sluis & Spek, 1990; Spek, 2015.
Spherical scattering factor approximation: Doyle & Turner, 1968; Dawson, 1964a,b; Coppens et al., 1969.
Multiple diffraction: Renninger, 1937.
λ/2 effects: Kirschbaum et al., 1997.
Radiation damage: Abrahams, 1973; Hope, 1975; Abrahams & Marsh, 1987; Moon et al., 2011; Christensen et al., 2019.
Diffuse scatter and satellite reflections: Bürgi, 2022; Stevens, 1974; Dornberger-Schiff, 1956; Zachariasen, 1967; Wagner & Schönleber, 2009; Petříček et al., 2014.
Supporting information
CCDC reference: 2231833
https://doi.org/10.1107/S2056989023002700/dj2064sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989023002700/dj2064Isup2.hkl
Background, points to consider and strategies for determining the best model. DOI: https://doi.org/10.1107/S2056989023002700/dj2064sup3.pdf
the .res file for the mono-selenide model. DOI: https://doi.org/10.1107/S2056989023002700/dj2064sup4.txt
the .res file for the di-selenide model. DOI: https://doi.org/10.1107/S2056989023002700/dj2064sup5.txt
the .res file for the free occupancy selenide model. DOI: https://doi.org/10.1107/S2056989023002700/dj2064sup6.txt
the .res file for the mixed selenide/sulfide model. DOI: https://doi.org/10.1107/S2056989023002700/dj2064sup7.txt
Data collection: APEX2 (Bruker, 2013); cell
APEX2 (Bruker, 2013); data reduction: APEX2 (Bruker, 2013); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2019/2 (Sheldrick, 2015b); molecular graphics: Olex2 (Dolomanov et al., 2009; Bourhis et al., 2015), Mercury (Macrae et al., 2020), ShelXle (Hübschle et al., 2011), CrystalExplorer (Spackman et al., 2021), CrystalMaker (Palmer, 2007); software used to prepare material for publication: SHELX (Sheldrick, 2008) and publCIF (Westrip, 2010).C26H22P2S1.13Se0.87 | Dx = 1.446 Mg m−3 |
Mr = 501.46 | Cu Kα radiation, λ = 1.54178 Å |
Orthorhombic, P212121 | Cell parameters from 9858 reflections |
a = 12.2833 (2) Å | θ = 3.1–72.1° |
b = 13.1643 (2) Å | µ = 4.32 mm−1 |
c = 14.2478 (2) Å | T = 173 K |
V = 2303.88 (6) Å3 | Block, yellow |
Z = 4 | 0.49 × 0.45 × 0.34 mm |
F(000) = 1023 |
Bruker APEXII CCD diffractometer | 4187 independent reflections |
Radiation source: microsource | 4155 reflections with I > 2σ(I) |
Detector resolution: 7.41 pixels mm-1 | Rint = 0.026 |
φ and ω scans | θmax = 72.0°, θmin = 4.6° |
Absorption correction: multi-scan (SADABS; Krause et al., 2015) | h = −13→14 |
Tmin = 0.587, Tmax = 0.754 | k = −15→16 |
24246 measured reflections | l = −17→17 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.021 | H-atom parameters constrained |
wR(F2) = 0.053 | w = 1/[σ2(Fo2) + (0.0259P)2 + 0.6437P] where P = (Fo2 + 2Fc2)/3 |
S = 1.10 | (Δ/σ)max < 0.001 |
4187 reflections | Δρmax = 0.25 e Å−3 |
279 parameters | Δρmin = −0.23 e Å−3 |
0 restraints | Absolute structure: Flack x determined using 1619 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013). |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.018 (5) |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
Refinement. Refinement progress was checked using Platon (Spek, 2020) and by an R-tensor (Parkin, 2000). The final model was further checked with the IUCr utility checkCIF. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Se1 | 0.5609 (7) | 0.3728 (6) | 0.1269 (5) | 0.0324 (6) | 0.487 (3) |
S1 | 0.5543 (16) | 0.3748 (14) | 0.1378 (11) | 0.0324 (6) | 0.513 (3) |
Se2 | 0.3955 (11) | 0.8180 (7) | −0.0416 (9) | 0.0290 (8) | 0.386 (3) |
S2 | 0.3917 (16) | 0.8053 (11) | −0.0401 (14) | 0.0290 (8) | 0.614 (3) |
P1 | 0.53848 (5) | 0.52619 (4) | 0.15679 (4) | 0.02193 (15) | |
P2 | 0.44544 (5) | 0.67007 (4) | −0.07209 (4) | 0.02106 (15) | |
C1 | 0.6036 (2) | 0.60331 (18) | 0.06839 (17) | 0.0247 (5) | |
H1 | 0.678166 | 0.615265 | 0.082046 | 0.030* | |
C2 | 0.5726 (2) | 0.64761 (18) | −0.01138 (17) | 0.0238 (5) | |
H2 | 0.632873 | 0.674300 | −0.045092 | 0.029* | |
C3 | 0.6118 (2) | 0.56693 (18) | 0.26141 (17) | 0.0236 (5) | |
C4 | 0.6416 (2) | 0.6674 (2) | 0.2747 (2) | 0.0348 (6) | |
H4 | 0.622485 | 0.717086 | 0.229226 | 0.042* | |
C5 | 0.6993 (3) | 0.6958 (2) | 0.3544 (2) | 0.0400 (7) | |
H5 | 0.719472 | 0.764842 | 0.363164 | 0.048* | |
C6 | 0.7273 (2) | 0.6241 (2) | 0.42085 (19) | 0.0340 (6) | |
H6 | 0.767453 | 0.643337 | 0.475021 | 0.041* | |
C7 | 0.6967 (2) | 0.5248 (2) | 0.4079 (2) | 0.0368 (7) | |
H7 | 0.715302 | 0.475575 | 0.453854 | 0.044* | |
C8 | 0.6394 (2) | 0.4953 (2) | 0.3293 (2) | 0.0317 (6) | |
H8 | 0.618731 | 0.426310 | 0.321502 | 0.038* | |
C9 | 0.3993 (2) | 0.56668 (18) | 0.17259 (17) | 0.0218 (5) | |
C10 | 0.3177 (2) | 0.4942 (2) | 0.17614 (18) | 0.0283 (6) | |
H10 | 0.335274 | 0.424196 | 0.170070 | 0.034* | |
C11 | 0.2103 (2) | 0.5237 (2) | 0.1886 (2) | 0.0351 (6) | |
H11 | 0.154201 | 0.474094 | 0.190052 | 0.042* | |
C12 | 0.1851 (2) | 0.6251 (2) | 0.1987 (2) | 0.0352 (6) | |
H12 | 0.111475 | 0.645133 | 0.207103 | 0.042* | |
C13 | 0.2660 (2) | 0.6977 (2) | 0.1968 (2) | 0.0328 (6) | |
H13 | 0.248108 | 0.767397 | 0.204846 | 0.039* | |
C14 | 0.3735 (2) | 0.6691 (2) | 0.18307 (18) | 0.0284 (6) | |
H14 | 0.429257 | 0.719055 | 0.180830 | 0.034* | |
C15 | 0.4883 (2) | 0.65684 (19) | −0.19416 (17) | 0.0249 (5) | |
C16 | 0.5588 (2) | 0.5791 (2) | −0.22096 (19) | 0.0330 (6) | |
H16 | 0.587585 | 0.533907 | −0.175276 | 0.040* | |
C17 | 0.5868 (2) | 0.5682 (3) | −0.3148 (2) | 0.0455 (8) | |
H17 | 0.635568 | 0.515905 | −0.333409 | 0.055* | |
C18 | 0.5438 (3) | 0.6331 (3) | −0.3812 (2) | 0.0478 (8) | |
H18 | 0.561813 | 0.624394 | −0.445494 | 0.057* | |
C19 | 0.4755 (3) | 0.7097 (3) | −0.3548 (2) | 0.0427 (8) | |
H19 | 0.447116 | 0.754619 | −0.400929 | 0.051* | |
C20 | 0.4470 (2) | 0.7225 (2) | −0.26115 (19) | 0.0322 (6) | |
H20 | 0.399383 | 0.775975 | −0.243210 | 0.039* | |
C21 | 0.3461 (2) | 0.56962 (18) | −0.05739 (17) | 0.0241 (5) | |
C22 | 0.3769 (2) | 0.46794 (19) | −0.06166 (18) | 0.0308 (6) | |
H22 | 0.451777 | 0.450049 | −0.064155 | 0.037* | |
C23 | 0.2976 (3) | 0.3930 (2) | −0.0622 (2) | 0.0379 (7) | |
H23 | 0.318227 | 0.323468 | −0.064779 | 0.045* | |
C24 | 0.1892 (3) | 0.4188 (2) | −0.0591 (2) | 0.0431 (8) | |
H24 | 0.135332 | 0.367069 | −0.060500 | 0.052* | |
C25 | 0.1579 (2) | 0.5197 (3) | −0.0541 (2) | 0.0434 (7) | |
H25 | 0.082874 | 0.536992 | −0.051575 | 0.052* | |
C26 | 0.2364 (2) | 0.5956 (2) | −0.05262 (19) | 0.0308 (6) | |
H26 | 0.215389 | 0.664886 | −0.048398 | 0.037* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Se1 | 0.0372 (10) | 0.0261 (4) | 0.0338 (16) | 0.0063 (5) | 0.0091 (10) | −0.0022 (9) |
S1 | 0.0372 (10) | 0.0261 (4) | 0.0338 (16) | 0.0063 (5) | 0.0091 (10) | −0.0022 (9) |
Se2 | 0.0335 (8) | 0.017 (2) | 0.0367 (4) | 0.0043 (14) | −0.0011 (5) | −0.0014 (14) |
S2 | 0.0335 (8) | 0.017 (2) | 0.0367 (4) | 0.0043 (14) | −0.0011 (5) | −0.0014 (14) |
P1 | 0.0201 (3) | 0.0209 (3) | 0.0248 (3) | 0.0025 (2) | 0.0022 (2) | 0.0025 (2) |
P2 | 0.0204 (3) | 0.0208 (3) | 0.0220 (3) | 0.0002 (3) | 0.0002 (2) | 0.0000 (2) |
C1 | 0.0179 (11) | 0.0297 (13) | 0.0266 (12) | −0.0028 (10) | 0.0015 (10) | 0.0006 (10) |
C2 | 0.0188 (12) | 0.0270 (12) | 0.0257 (12) | −0.0018 (9) | 0.0015 (9) | −0.0016 (9) |
C3 | 0.0199 (12) | 0.0272 (12) | 0.0238 (12) | 0.0052 (10) | 0.002 (1) | 0.0034 (10) |
C4 | 0.0413 (16) | 0.0288 (13) | 0.0342 (14) | 0.0031 (12) | −0.0110 (12) | 0.0067 (11) |
C5 | 0.0461 (17) | 0.0342 (15) | 0.0397 (16) | 0.0021 (13) | −0.0112 (14) | 0.0000 (13) |
C6 | 0.0269 (13) | 0.0500 (16) | 0.0253 (13) | 0.0059 (13) | −0.0039 (11) | 0.0015 (12) |
C7 | 0.0303 (14) | 0.0482 (17) | 0.0318 (14) | 0.0078 (13) | −0.0021 (12) | 0.0178 (13) |
C8 | 0.0287 (14) | 0.0316 (13) | 0.0350 (14) | 0.0038 (11) | 0.0024 (12) | 0.0119 (11) |
C9 | 0.0195 (11) | 0.0240 (11) | 0.0219 (11) | 0.0003 (10) | 0.0022 (10) | 0.0004 (9) |
C10 | 0.0276 (13) | 0.0263 (13) | 0.0312 (13) | −0.0050 (11) | 0.0045 (11) | −0.0004 (11) |
C11 | 0.0237 (13) | 0.0425 (16) | 0.0393 (16) | −0.0091 (12) | 0.0070 (12) | −0.0019 (13) |
C12 | 0.0206 (13) | 0.0506 (16) | 0.0345 (14) | 0.0065 (13) | 0.0053 (11) | −0.0017 (13) |
C13 | 0.0298 (15) | 0.0299 (14) | 0.0387 (15) | 0.0083 (12) | 0.0024 (12) | −0.0046 (11) |
C14 | 0.0256 (13) | 0.0267 (12) | 0.0329 (13) | −0.0022 (11) | 0.0002 (11) | −0.0014 (11) |
C15 | 0.0196 (12) | 0.0323 (14) | 0.0227 (12) | −0.0076 (10) | −0.0006 (9) | −0.0024 (10) |
C16 | 0.0255 (13) | 0.0417 (14) | 0.0318 (13) | −0.0013 (13) | −0.0001 (12) | −0.0085 (12) |
C17 | 0.0290 (16) | 0.064 (2) | 0.0436 (18) | −0.0032 (15) | 0.0073 (13) | −0.0202 (15) |
C18 | 0.0373 (17) | 0.080 (2) | 0.0257 (14) | −0.0235 (18) | 0.0070 (13) | −0.0069 (15) |
C19 | 0.0452 (18) | 0.0580 (19) | 0.0250 (13) | −0.0177 (15) | −0.0022 (13) | 0.0084 (13) |
C20 | 0.0331 (14) | 0.0324 (13) | 0.0310 (13) | −0.0065 (12) | −0.0036 (13) | 0.0025 (11) |
C21 | 0.0245 (12) | 0.0256 (12) | 0.0223 (12) | −0.0031 (10) | 0.0015 (10) | −0.001 (1) |
C22 | 0.0333 (15) | 0.0271 (13) | 0.0321 (14) | 0.0001 (11) | 0.0062 (12) | −0.0013 (11) |
C23 | 0.0496 (18) | 0.0292 (14) | 0.0348 (15) | −0.0089 (13) | 0.0087 (13) | −0.0036 (12) |
C24 | 0.0457 (18) | 0.0461 (17) | 0.0375 (16) | −0.0249 (15) | 0.0081 (14) | −0.0064 (14) |
C25 | 0.0254 (14) | 0.0600 (19) | 0.0448 (17) | −0.0114 (14) | 0.0044 (13) | −0.0066 (15) |
C26 | 0.0255 (13) | 0.0344 (14) | 0.0327 (14) | −0.0004 (11) | 0.0045 (11) | −0.0032 (11) |
Se1—P1 | 2.082 (8) | C11—H11 | 0.9500 |
S1—P1 | 2.021 (19) | C12—C13 | 1.379 (4) |
Se2—P2 | 2.088 (11) | C12—H12 | 0.9500 |
S2—P2 | 1.953 (16) | C13—C14 | 1.387 (4) |
P1—C1 | 1.805 (2) | C13—H13 | 0.9500 |
P1—C9 | 1.805 (2) | C14—H14 | 0.9500 |
P1—C3 | 1.822 (3) | C15—C20 | 1.384 (4) |
P2—C2 | 1.810 (2) | C15—C16 | 1.394 (4) |
P2—C21 | 1.812 (2) | C16—C17 | 1.388 (4) |
P2—C15 | 1.826 (2) | C16—H16 | 0.9500 |
C1—C2 | 1.333 (3) | C17—C18 | 1.379 (5) |
C1—H1 | 0.9500 | C17—H17 | 0.9500 |
C2—H2 | 0.9500 | C18—C19 | 1.364 (5) |
C3—C4 | 1.386 (4) | C18—H18 | 0.9500 |
C3—C8 | 1.392 (4) | C19—C20 | 1.390 (4) |
C4—C5 | 1.389 (4) | C19—H19 | 0.9500 |
C4—H4 | 0.9500 | C20—H20 | 0.9500 |
C5—C6 | 1.381 (4) | C21—C26 | 1.391 (4) |
C5—H5 | 0.9500 | C21—C22 | 1.392 (4) |
C6—C7 | 1.373 (4) | C22—C23 | 1.387 (4) |
C6—H6 | 0.9500 | C22—H22 | 0.9500 |
C7—C8 | 1.378 (4) | C23—C24 | 1.375 (5) |
C7—H7 | 0.9500 | C23—H23 | 0.9500 |
C8—H8 | 0.9500 | C24—C25 | 1.384 (5) |
C9—C10 | 1.385 (4) | C24—H24 | 0.9500 |
C9—C14 | 1.393 (3) | C25—C26 | 1.389 (4) |
C10—C11 | 1.386 (4) | C25—H25 | 0.9500 |
C10—H10 | 0.9500 | C26—H26 | 0.9500 |
C11—C12 | 1.378 (4) | ||
C1—P1—C9 | 109.91 (11) | C12—C11—C10 | 119.9 (3) |
C1—P1—C3 | 100.74 (12) | C12—C11—H11 | 120.0 |
C9—P1—C3 | 106.22 (11) | C10—C11—H11 | 120.0 |
C1—P1—S1 | 114.8 (5) | C11—C12—C13 | 120.5 (3) |
C9—P1—S1 | 113.5 (6) | C11—C12—H12 | 119.7 |
C3—P1—S1 | 110.6 (6) | C13—C12—H12 | 119.7 |
C1—P1—Se1 | 110.1 (2) | C12—C13—C14 | 120.0 (3) |
C9—P1—Se1 | 115.9 (2) | C12—C13—H13 | 120.0 |
C3—P1—Se1 | 112.8 (2) | C14—C13—H13 | 120.0 |
C2—P2—C21 | 114.01 (12) | C13—C14—C9 | 119.7 (2) |
C2—P2—C15 | 100.99 (11) | C13—C14—H14 | 120.2 |
C21—P2—C15 | 103.59 (11) | C9—C14—H14 | 120.2 |
C2—P2—S2 | 109.2 (6) | C20—C15—C16 | 119.8 (2) |
C21—P2—S2 | 114.3 (6) | C20—C15—P2 | 119.4 (2) |
C15—P2—S2 | 114.0 (6) | C16—C15—P2 | 120.7 (2) |
C2—P2—Se2 | 107.8 (4) | C17—C16—C15 | 119.6 (3) |
C21—P2—Se2 | 117.3 (4) | C17—C16—H16 | 120.2 |
C15—P2—Se2 | 111.9 (4) | C15—C16—H16 | 120.2 |
C2—C1—P1 | 135.6 (2) | C18—C17—C16 | 120.1 (3) |
C2—C1—H1 | 112.2 | C18—C17—H17 | 120.0 |
P1—C1—H1 | 112.2 | C16—C17—H17 | 120.0 |
C1—C2—P2 | 136.5 (2) | C19—C18—C17 | 120.3 (3) |
C1—C2—H2 | 111.7 | C19—C18—H18 | 119.8 |
P2—C2—H2 | 111.7 | C17—C18—H18 | 119.8 |
C4—C3—C8 | 119.1 (2) | C18—C19—C20 | 120.6 (3) |
C4—C3—P1 | 121.56 (19) | C18—C19—H19 | 119.7 |
C8—C3—P1 | 119.3 (2) | C20—C19—H19 | 119.7 |
C3—C4—C5 | 120.2 (3) | C15—C20—C19 | 119.6 (3) |
C3—C4—H4 | 119.9 | C15—C20—H20 | 120.2 |
C5—C4—H4 | 119.9 | C19—C20—H20 | 120.2 |
C6—C5—C4 | 120.2 (3) | C26—C21—C22 | 120.1 (2) |
C6—C5—H5 | 119.9 | C26—C21—P2 | 118.59 (19) |
C4—C5—H5 | 119.9 | C22—C21—P2 | 120.9 (2) |
C7—C6—C5 | 119.3 (3) | C23—C22—C21 | 119.6 (3) |
C7—C6—H6 | 120.3 | C23—C22—H22 | 120.2 |
C5—C6—H6 | 120.3 | C21—C22—H22 | 120.2 |
C6—C7—C8 | 121.2 (3) | C24—C23—C22 | 120.2 (3) |
C6—C7—H7 | 119.4 | C24—C23—H23 | 119.9 |
C8—C7—H7 | 119.4 | C22—C23—H23 | 119.9 |
C7—C8—C3 | 119.8 (3) | C23—C24—C25 | 120.5 (3) |
C7—C8—H8 | 120.1 | C23—C24—H24 | 119.7 |
C3—C8—H8 | 120.1 | C25—C24—H24 | 119.7 |
C10—C9—C14 | 119.9 (2) | C24—C25—C26 | 119.9 (3) |
C10—C9—P1 | 119.12 (19) | C24—C25—H25 | 120.1 |
C14—C9—P1 | 120.98 (19) | C26—C25—H25 | 120.1 |
C9—C10—C11 | 120.0 (2) | C25—C26—C21 | 119.7 (3) |
C9—C10—H10 | 120.0 | C25—C26—H26 | 120.2 |
C11—C10—H10 | 120.0 | C21—C26—H26 | 120.2 |
C9—P1—C1—C2 | −35.3 (3) | C11—C12—C13—C14 | 1.0 (4) |
C3—P1—C1—C2 | −147.1 (3) | C12—C13—C14—C9 | −0.9 (4) |
S1—P1—C1—C2 | 94.1 (7) | C10—C9—C14—C13 | −0.2 (4) |
Se1—P1—C1—C2 | 93.6 (4) | P1—C9—C14—C13 | −178.8 (2) |
P1—C1—C2—P2 | 9.0 (5) | C2—P2—C15—C20 | −140.0 (2) |
C21—P2—C2—C1 | −34.1 (3) | C21—P2—C15—C20 | 101.8 (2) |
C15—P2—C2—C1 | −144.5 (3) | S2—P2—C15—C20 | −23.0 (7) |
S2—P2—C2—C1 | 95.1 (6) | Se2—P2—C15—C20 | −25.5 (4) |
Se2—P2—C2—C1 | 98.1 (5) | C2—P2—C15—C16 | 42.5 (2) |
C1—P1—C3—C4 | 38.4 (3) | C21—P2—C15—C16 | −75.8 (2) |
C9—P1—C3—C4 | −76.2 (2) | S2—P2—C15—C16 | 159.5 (6) |
S1—P1—C3—C4 | 160.2 (6) | Se2—P2—C15—C16 | 156.9 (4) |
Se1—P1—C3—C4 | 155.8 (3) | C20—C15—C16—C17 | −0.1 (4) |
C1—P1—C3—C8 | −141.1 (2) | P2—C15—C16—C17 | 177.4 (2) |
C9—P1—C3—C8 | 104.3 (2) | C15—C16—C17—C18 | −0.9 (4) |
S1—P1—C3—C8 | −19.3 (6) | C16—C17—C18—C19 | 1.4 (5) |
Se1—P1—C3—C8 | −23.7 (3) | C17—C18—C19—C20 | −0.9 (5) |
C8—C3—C4—C5 | 0.7 (4) | C16—C15—C20—C19 | 0.6 (4) |
P1—C3—C4—C5 | −178.8 (2) | P2—C15—C20—C19 | −177.0 (2) |
C3—C4—C5—C6 | 0.0 (5) | C18—C19—C20—C15 | 0.0 (4) |
C4—C5—C6—C7 | −0.7 (5) | C2—P2—C21—C26 | 145.1 (2) |
C5—C6—C7—C8 | 0.6 (4) | C15—P2—C21—C26 | −106.1 (2) |
C6—C7—C8—C3 | 0.1 (4) | S2—P2—C21—C26 | 18.5 (7) |
C4—C3—C8—C7 | −0.8 (4) | Se2—P2—C21—C26 | 17.7 (5) |
P1—C3—C8—C7 | 178.8 (2) | C2—P2—C21—C22 | −42.3 (2) |
C1—P1—C9—C10 | 133.8 (2) | C15—P2—C21—C22 | 66.5 (2) |
C3—P1—C9—C10 | −118.1 (2) | S2—P2—C21—C22 | −168.9 (7) |
S1—P1—C9—C10 | 3.7 (6) | Se2—P2—C21—C22 | −169.7 (4) |
Se1—P1—C9—C10 | 8.1 (3) | C26—C21—C22—C23 | 0.8 (4) |
C1—P1—C9—C14 | −47.5 (2) | P2—C21—C22—C23 | −171.8 (2) |
C3—P1—C9—C14 | 60.6 (2) | C21—C22—C23—C24 | 0.4 (4) |
S1—P1—C9—C14 | −177.6 (5) | C22—C23—C24—C25 | −0.9 (5) |
Se1—P1—C9—C14 | −173.2 (3) | C23—C24—C25—C26 | 0.4 (5) |
C14—C9—C10—C11 | 1.1 (4) | C24—C25—C26—C21 | 0.7 (4) |
P1—C9—C10—C11 | 179.8 (2) | C22—C21—C26—C25 | −1.3 (4) |
C9—C10—C11—C12 | −0.9 (4) | P2—C21—C26—C25 | 171.4 (2) |
C10—C11—C12—C13 | −0.1 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1···Se2i | 0.95 | 2.87 | 3.752 (13) | 155 |
C1—H1···S2i | 0.95 | 2.89 | 3.76 (2) | 153 |
C8—H8···Se1 | 0.95 | 2.95 | 3.443 (8) | 114 |
C8—H8···S1 | 0.95 | 2.82 | 3.325 (18) | 115 |
C10—H10···Se1 | 0.95 | 2.92 | 3.459 (8) | 117 |
C10—H10···S1 | 0.95 | 2.81 | 3.349 (19) | 117 |
C20—H20···Se2 | 0.95 | 2.93 | 3.431 (13) | 115 |
C20—H20···S2 | 0.95 | 2.92 | 3.40 (2) | 113 |
C26—H26···Se2 | 0.95 | 3.00 | 3.524 (11) | 117 |
C26—H26···S2 | 0.95 | 2.85 | 3.361 (17) | 115 |
Symmetry code: (i) x+1/2, −y+3/2, −z. |
h k l | Fobs2 | Fcalc2 | error/s.u. | Fcalc/Fcalc(max) | d–spacing (Å) |
1 0 2 | 250.91 | 6.81 | 10.42 | 0.012 | 6.16 |
0 3 2 | 1787.72 | 504.88 | 10.20 | 0.101 | 3.74 |
2 0 3 | 335.44 | 41.35 | 9.52 | 0.029 | 3.76 |
1 4 0 | 671.93 | 175.18 | 8.75 | 0.060 | 3.18 |
All of the worst fitting reflections above have Fobs2 >> Fcalc2 and none would be obscured by a well-designed beamstop. |
h k l | Fobs2 | Fcalc2 | error/s.u. | Fcalc/Fcalc(max) | d–spacing (Å) |
1 2 0 | 14663.16 | 2109.28 | 11.62 | 0.181 | 5.80 |
4 2 0 | 1787.72 | 13.29 | 10.10 | 0.014 | 2.78 |
0 4 3 | 335.44 | 114.61 | 10.00 | 0.042 | 2.71 |
0 2 0 | 671.93 | 1634.82 | 9.55 | 0.159 | 6.58 |
Three of the worst fitting reflections above have Fobs2 >> Fcalc2 and none would be obscured by a well-designed beamstop. |
h k l | Fobs2 | Fcalc2 | error/s.u. | Fcalc/Fcalc(max) | d–spacing (Å) |
6 3 0 | 275.52 | 151.58 | 7.71 | 0.053 | 1.86 |
1 0 2 | 344.63 | 207.43 | 7.69 | 0.062 | 6.16 |
0 0 2 | 118.70 | 64.07 | 5.83 | 0.034 | 7.12 |
0 2 1 | 20.03 | 3.69 | 5.55 | 0.008 | 5.98 |
There are no egregious Fobs2 vs Fcalc2 mis-matches for this model. |
h k l | Fobs2 | Fcalc2 | error/s.u. | Fcalc/Fcalc(max) | d–spacing (Å) |
6 3 0 | 270.87 | 165.41 | 7.11 | 0.055 | 1.86 |
0 8 0 | 301.14 | 215.46 | 5.07 | 0.063 | 1.65 |
0 6 2 | 784.43 | 965.40 | 4.86 | 0.133 | 2.10 |
2 5 1 | 57.90 | 29.40 | 4.80 | 0.023 | 2.39 |
There are no egregious Fobs2 vs Fcalc2 misfits for this model. |
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1···Se2i | 0.95 | 2.87 | 3.752 (13) | 155.1 |
C1—H1···S2i | 0.95 | 2.89 | 3.76 (2) | 153.4 |
C8—H8···Se1 | 0.95 | 2.95 | 3.443 (8) | 113.8 |
C8—H8···S1 | 0.95 | 2.82 | 3.325 (18) | 114.5 |
C10—H10···Se1 | 0.95 | 2.92 | 3.459 (8) | 117.4 |
C10—H10···S1 | 0.95 | 2.81 | 3.349 (19) | 117.2 |
C20—H20···Se2 | 0.95 | 2.93 | 3.431 (13) | 114.5 |
C20—H20···S2 | 0.95 | 2.92 | 3.40 (2) | 112.6 |
C26—H26···Se2 | 0.95 | 3.00 | 3.524 (11) | 116.6 |
C26—H26···S2 | 0.95 | 2.85 | 3.361 (17) | 114.8 |
Symmetry code: (i) x + 1/2, -y + 3/2, -z. |
Acknowledgements
We are grateful to the GVSU Chemistry Department Weldon Fund for support of this work. The CCD-based X-ray diffractometers at Michigan State University were upgraded and/or replaced using departmental funds.
Funding information
Funding for this research was provided by: NSF (RUI CHE-2102576) to SB at GVSU) and GVSU CSCE Research Grant-in-Aid to B. Rawls.
References
Abrahams, S. C. (1973). Acta Cryst. A29, 111–116. CrossRef IUCr Journals Web of Science Google Scholar
Abrahams, S. C. & Marsh, P. (1987). Acta Cryst. A43, 265–269. CrossRef CAS Web of Science IUCr Journals Google Scholar
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–S19. CrossRef Web of Science Google Scholar
Artioli, G., Masciocchi, N. & Galli, E. (1997). Acta Cryst. B53, 498–503. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Baur, W. H. & Kassner, D. (1992). Acta Cryst. B48, 356–369. CrossRef CAS Web of Science IUCr Journals Google Scholar
Becker, P. J. & Coppens, P. (1974). Acta Cryst. A30, 129–147. CrossRef IUCr Journals Web of Science Google Scholar
Blessing, R. H. (1995). Acta Cryst. A51, 33–38. CrossRef CAS Web of Science IUCr Journals Google Scholar
Bourhis, L. J., Dolomanov, O. V., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2015). Acta Cryst. A71, 59–75. Web of Science CrossRef IUCr Journals Google Scholar
Bruker (2013). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruno, I. J., Cole, J. C., Kessler, M., Luo, J., Motherwell, W. D. S., Purkis, L. H., Smith, B. R., Taylor, R., Cooper, R. I., Harris, S. E. & Orpen, A. G. (2004). J. Chem. Inf. Comput. Sci. 44, 2133–2144. Web of Science CrossRef PubMed CAS Google Scholar
Bürgi, H.-B. (2022). Acta Cryst. B78, 283–289. CrossRef IUCr Journals Google Scholar
Christensen, J., Horton, P. N., Bury, C. S., Dickerson, J. L., Taberman, H., Garman, E. F. & Coles, S. J. (2019). IUCrJ, 6, 703–713. Web of Science CSD CrossRef CAS PubMed IUCr Journals Google Scholar
Clegg, W. (2019). Acta Cryst. E75, 1812–1819. Web of Science CrossRef IUCr Journals Google Scholar
Cooper, R. I., Gould, R. O., Parsons, S. & Watkin, D. J. (2002). J. Appl. Cryst. 35, 168–174. Web of Science CrossRef CAS IUCr Journals Google Scholar
Coppens, P., Sabine, T. M., Delaplane, G. & Ibers, J. A. (1969). Acta Cryst. B25, 2451–2458. CrossRef CAS IUCr Journals Web of Science Google Scholar
Darwin, C. G. (1914a). London, Edinb. Dubl. Philos. Mag. J. Sci. 27, 315–333. Google Scholar
Darwin, C. G. (1914b). London, Edinb. Dubl. Philos. Mag. J. Sci. 27, 675–690. Google Scholar
Dawson, B. (1964a). Acta Cryst. 17, 990–996. CrossRef IUCr Journals Web of Science Google Scholar
Dawson, B. (1964b). Acta Cryst. 17, 997–1009. CrossRef CAS IUCr Journals Web of Science Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Donnay, J. D. H. & Donnay, G. (1959). International Tables for X-ray Crystallography, vol. II, p104. Birmingham, Kynoch Press. Google Scholar
Dornberger-Schiff, K. (1956). Acta Cryst. 9, 593–601. CrossRef CAS IUCr Journals Web of Science Google Scholar
Doyle, P. A. & Turner, P. S. (1968). Acta Cryst. A24, 390–397. CrossRef IUCr Journals Web of Science Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CrossRef IUCr Journals Google Scholar
Haestier, J., Sadki, M., Thompson, A. L. & Watkin, D. (2008). J. Appl. Cryst. 41, 531–536. Web of Science CrossRef CAS IUCr Journals Google Scholar
Hahn, Th. & Klapper, H. (2006). International Tables for Crystallography, vol. D, pp. 393–448. Chester: International Union of Crystallography. Google Scholar
Herbst-Irmer, R. & Sheldrick, G. M. (1998). Acta Cryst. B54, 443–449. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Herbst-Irmer, R. & Sheldrick, G. M. (2002). Acta Cryst. B58, 477–481. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Hope, H. (1975). In Anomalous Scattering edited by S. Ramaseshan & S. C. Abrahams, Copenhagen: IUCr, Munksgaard. Google Scholar
Hübschle, C. B., Sheldrick, G. M. & Dittrich, B. (2011). J. Appl. Cryst. 44, 1281–1284. Web of Science CrossRef IUCr Journals Google Scholar
Jones, P. G., Hrib, C. & du Mont, W.-W. (2015). Private Communication (refcode YOWTIP) CCDC, Cambridge, England. Google Scholar
Kirschbaum, K., Martin, A. & Pinkerton, A. A. (1997). J. Appl. Cryst. 30, 514–516. CrossRef CAS Web of Science IUCr Journals Google Scholar
Krause, L., Herbst-Irmer, R., Sheldrick, G. M. & Stalke, D. (2015). J. Appl. Cryst. 48, 3–10. Web of Science CSD CrossRef ICSD CAS IUCr Journals Google Scholar
Larson, A. C. (1967). Acta Cryst. 23, 664–665. CrossRef IUCr Journals Web of Science Google Scholar
Le Page, Y. (1987). J. Appl. Cryst. 20, 264–269. CrossRef CAS Web of Science IUCr Journals Google Scholar
Le Page, Y. (1988). J. Appl. Cryst. 21, 983–984. CrossRef Web of Science IUCr Journals Google Scholar
Linden, A. (2020). Acta Cryst. E76, 765–775. Web of Science CrossRef IUCr Journals Google Scholar
Luster, T., Van de Roovaart, H. J., Korman, K. J., Sands, G. G., Dunn, K. M., Spyker, A., Staples, R. J., Biros, S. M. & Bender, J. E. (2022). Dalton Trans. 51, 9103–9115. CSD CrossRef CAS PubMed Google Scholar
Macrae, C. F., Sovago, I., Cottrell, S. J., Galek, P. T. A., McCabe, P., Pidcock, E., Platings, M., Shields, G. P., Stevens, J. S., Towler, M. & Wood, P. A. (2020). J. Appl. Cryst. 53, 226–235. Web of Science CrossRef CAS IUCr Journals Google Scholar
Marsh, R. E. (1997). Acta Cryst. B53, 317–322. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Marsh, R. E. & Spek, A. L. (2001). Acta Cryst. B57, 800–805. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Meulenaer, J. de & Tompa, H. (1965). Acta Cryst. 19, 1014–1018. CrossRef IUCr Journals Web of Science Google Scholar
Mohamed, S. K., Younes, S. H. H., Abdel-Raheem, E. M. M., Horton, P. N., Akkurt, M. & Glidewell, C. (2016). Acta Cryst. C72, 57–62. Web of Science CSD CrossRef IUCr Journals Google Scholar
Moon, D. K., Tripathi, A., Sullivan, D., Siegler, M. A., Parkin, S. & Posner, G. H. (2011). Bioorg. Med. Chem. Lett. 21, 2773–2775. CSD CrossRef CAS PubMed Google Scholar
Morse, P. T., Staples, R. J. & Biros, S. M. (2016). Polyhedron, 114, 2–12. Web of Science CSD CrossRef CAS Google Scholar
Mugemana, J., Bender, J., Staples, R. J. & Biros, S. M. (2018). Acta Cryst. E74, 998–1001. CSD CrossRef IUCr Journals Google Scholar
Neils, T., LaDuca, A., Bender, J. E., Staples, R. J. & Biros, S. M. (2022). Acta Cryst. E78, 1044–1047. CSD CrossRef IUCr Journals Google Scholar
Nespolo, M. (2015). Cryst. Res. Technol. 50, 362–371. Web of Science CrossRef CAS Google Scholar
Nespolo, M. (2019). Acta Cryst. A75, 551–573. Web of Science CrossRef IUCr Journals Google Scholar
Nespolo, M. & Ferraris, G. (2003). Z. Kristallogr. 218, 178–181. Web of Science CrossRef CAS Google Scholar
Nespolo, M., Smaha, R. W. & Parkin, S. (2020). Acta Cryst. B76, 643–649. Web of Science CrossRef IUCr Journals Google Scholar
Orpen, A. G., Brammer, L., Allen, F. H., Kennard, O., Watson, D. G. & Taylor, R. (1989). J. Chem. Soc. Dalton Trans. pp. S1. Google Scholar
Palmer, D. (2007). CrystalMaker. CrystalMaker Software Ltd, Yarnton, England. Google Scholar
Parkin, G. (1992). Acc. Chem. Res. 25, 455–460. CrossRef CAS Web of Science Google Scholar
Parkin, S., Glidewell, C. & Horton, P. N. (2023). Acta Cryst. C79, 77–82. CSD CrossRef IUCr Journals Google Scholar
Parkin, S. & Hope, H. (1998). Acta Cryst. B54, 339–344. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Parkin, S. R. (2021). Acta Cryst. E77, 452–465. Web of Science CrossRef IUCr Journals Google Scholar
Parsons, S. (2003). Acta Cryst. D59, 1995–2003. Web of Science CrossRef CAS IUCr Journals Google Scholar
Parsons, S., Flack, H. D. & Wagner, T. (2013). Acta Cryst. B69, 249–259. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Petříček, V., Dušek, M. & Plášil, J. (2014). Z. Kristallogr. 229, 345–352. Google Scholar
Prince, E. (2006). International Tables for Crystallography, vol. C. Table 9.5.1.1. Chester: International Union of Crystallography. Google Scholar
Rawls, B., Cunningham, J., Bender, J. E., Staples, R. J. & Biros, S. M. (2023). Acta Cryst. E79, 28–32. CSD CrossRef IUCr Journals Google Scholar
Renninger, M. (1937). Z. Phys. 106, 141–176. CrossRef CAS Google Scholar
Schomaker, V. & Trueblood, K. N. (1968). Acta Cryst. B24, 63–76. CrossRef CAS IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sluis, P. van der & Spek, A. L. (1990). Acta Cryst. A46, 194–201. CrossRef Web of Science IUCr Journals Google Scholar
Spackman, P. R., Turner, M. J., McKinnon, J. J., Wolff, S. K., Grimwood, D. J., Jayatilaka, D. & Spackman, M. A. (2021). J. Appl. Cryst. 54, 1006–1011. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2015). Acta Cryst. C71, 9–18. Web of Science CrossRef IUCr Journals Google Scholar
Spek, A. L. (2020). Acta Cryst. E76, 1–11. Web of Science CrossRef IUCr Journals Google Scholar
Stevens, E. D. (1974). Acta Cryst. A30, 184–189. CrossRef IUCr Journals Web of Science Google Scholar
Vinaya, Basavaraju, Y. B., Srinivasa, G. R., Shreenivas, M. T., Yathirajan, H. S. & Parkin, S. (2023). Acta Cryst. E79, 54–59. Web of Science CSD CrossRef IUCr Journals Google Scholar
Wagner, T. & Schönleber, A. (2009). Acta Cryst. B65, 249–268. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Watkin, D. (1994). Acta Cryst. A50, 411–437. CrossRef CAS Web of Science IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zachariasen, W. H. (1967). Acta Cryst. 23, 44–49. CrossRef IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.