research communications
κO)bis(2-methylpyridine-κN)copper(II)
and Hirshfeld surface analysis of dichlorido(methanol-aDepartment of Chemistry, School of Sciences, Indrashil University, Rajpur, Gujarat, 382740, India
*Correspondence e-mail: j.prakashareddy@gmail.com
In the title complex, [CuCl2(C6H7N)2(CH3OH)], the copper atom is five-coordinated by two nitrogen atoms of 2-methylpyridine ligands, two chloro ligands and an oxygen atom of the methanol molecule, being in a tetragonal–pyramidal environment with N and Cl atoms forming the basal plane. In the crystal, complex molecules related by the twofold rotation axis are joined into dimeric units by pairs of O—H⋯Cl hydrogen bonds. These dimeric units are assembled through C—H⋯Cl interactions into layers parallel to (001).
Keywords: crystal structure; hydrogen bonding; α-picoline; coordination chemistry.
CCDC reference: 1997065
1. Chemical context
Both organic (from simple molecules to et al., 2011; Gellman, 1998; Thorat et al., 2013; Vijayadas et al., 2013; Ziach et al., 2018). Recently, coordination compounds have been reported that find applications in fields such as catalysis, gas storage, separation technology and molecular sensing (Mueller et al., 2006; Wan et al., 2006; Férey et al., 2003; James, 2003; Eddaoudi et al., 2002; Ruben et al., 2005, Kitagawa et al., 2004). There are many reports of coordination complexes where solvent molecules are located in the voids of the However, reports describing the replacement of coordinated solvent molecules with other molecules are relatively scarce. As part of ongoing work in our laboratory, employing pyridine ligands in the preparation of various coordination networks (PrakashaReddy & Pedireddi, 2007), we have extended our work to the synthesis of other coordination networks. A literature survey revealed that coordination complex aquadichlorobis(2-methylpyridine)copper(II) had been reported (Marsh et al., 1982). Our interest was to see whether we could replace the coordinated water molecule in the complex with other solvent molecules such as methanol or ethanol via single-crystal-to-single-crystal transition (SCSCT) to investigate the structural changes. Although we could not succeed in SCSCT of the complex, we were successful in synthesizing the methanol-coordinated copper complex incorporating 2-methylpyridine as reported herein.
and proteins) and inorganic complexes have been known for more than a century and are central to modern chemistry because of their fascinating, aesthetic architectures and multiple applications (Gan2. Structural commentary
The title complex crystallizes in the monoclinic C2/c with one complex molecule per Two nitrogen atoms of 2-methylpyridine and two chloride ligands, which are trans to each other, form a rectangle around the copper atom, and its coordination is accomplished by the methanol oxygen atom, thus giving a tetragonal pyramid with the oxygen atom in the apical position (Fig. 1). The copper atom deviates by 0.161 (1) Å from the basal plane, and the angles around the copper atom are close to 90 and 180°. A plausible reason why the formation of a dimeric unit, as observed in [Cu(2-pic)2Cl2] (Marsh et al., 1982), was precluded might be the presence of the coordinated methanol molecule on one side of the coordination rectangle and the methyl groups on the other side. The methylpyridine rings form angles of 83.96 (8) and 85.70 (8)° with respect to the basal plane of the thereby plausibly blocking the sixth coordination position at the copper atom. The Cu—O bond distance of 2.353 (2) Å is relatively short for an apical atom in typical copper(II) tetragonal–pyramidal structure, whereas the Cu—N bond lengths [Cu1—N1= 2.031 (2) Å, Cu1—N2 = 2.017 (2) Å] agree well with those reported for related structures (Wang et al., 2006; Gong et al., 2009; Hu & Zhang, 2010; Li, 2011; Sun et al., 2013; Sanram et al., 2016).
3. Supramolecular features and Hirshfeld surface analysis
Complex molecules related by the twofold rotation axis are connected by pairs of O—H⋯Cl interactions (Table 1) involving the apical methanol ligand of one complex and a chloride ligand of the other, thus forming dimers (Fig. 2). The O⋯Cl and H⋯Cl distances and associated O—H⋯Cl angle lie within the ranges observed for other O—H⋯Cl interactions reported in the literature (Veal et al., 1972; Taylor, 2016; Ristić et al., 2020; Estes et al., 1976). These dimers are further connected through C—H⋯Cl interactions, generating layers parallel to (001) (Fig. 3, Table 1).
A Hirshfeld surface analysis was performed and two-dimensional fingerprint plots were prepared using Crystal Explorer17 (Turner et al., 2017) to further investigate the intermolecular interactions in the title structure. The Hirshfeld surface mapped over dnorm with corresponding colours representing intermolecular interactions is shown in Fig. 4. The red spots on the surface correspond to the O—H⋯Cl, C—H⋯Cl and C—H⋯O interactions (Table 1). The two-dimensional fingerprint plots (McKinnon et al., 2007) are shown in Fig. 5. Weak van der Waals H⋯H contacts make the largest contribution (53.1%) to the Hirshfeld surface. The two-dimensional fingerprint plot shows two spikes that correspond to H⋯Cl/Cl⋯H (25.2%) interactions, which highlight the hydrogen bonds between adjacent molecules. The C⋯H/H⋯C (15.5%) interactions also appear as two spikes. These interactions play a crucial role in the overall cohesion of the crystal packing.
4. Database survey
A search of the Cambridge Structural Database (CSD, Version 5.40, update of August 2019; Groom et al., 2016) revealed three closely related complexes: dichlorobis(2-methylpyridine)copper(II) (refcode CMPYCU01; Marsh et al., 1982), aquadichlorobis(2-methylpyridine)copper(II) (BIJWUM; Marsh et al., 1982) and bis(isothiocyanato)methanolbis(2-methylpyridine)copper(II) (ABOSIW; Handy et al., 2017). Structures CMPYCU01 and BIJWUM display dimeric arrangements of the complex molecules arising from C—H⋯Cl and O—H⋯Cl interactions, respectively, while in the copper(II) thiocyanate complex ABOSIW, the three-dimensional network is formed as a result of O—H⋯S, C—H⋯S and C—H⋯C interactions.
5. Synthesis and crystallization
2-Methylpyridine and anhydrous copper(II) chloride were obtained from Aldrich, and HPLC grade methanol was used for reaction. Anhydrous copper(II) chloride (0.675 g, 0.005 mol) was dissolved in 15 ml of methanol. To this solution, 2-methylpyridine (0.93 g, 0.01 mol) dissolved in 15 mL of methanol was added. The resulting mixture was stirred for ca 40 min. at room temperature and filtered to remove the greenish precipitate. The blue filtrate was then allowed to stand at room temperature for a few hours, before being filtered and left at room temperature for crystallization. A mixture of dark-blue crystals of different sizes was obtained after 24 h.
6. Refinement
Crystal data, data collection and structure . All H atoms were located in a difference map. The C-bound H atoms were placed in calculated positions with C—H = 0.93-0.96 Å and refined as riding, whereas the coordinates of O-bound H atom were freely refined. All hydrogen atoms were refined with fixed isotropic displacement parameters [Uiso(H) = 1.2–1.5Ueq(C,O)]
details are summarized in Table 2
|
Supporting information
CCDC reference: 1997065
https://doi.org/10.1107/S2056989020014036/yk2140sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989020014036/yk2140Isup2.hkl
Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell
CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: ShelXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).[CuCl2(C6H7N)2(CH4O)] | F(000) = 1448 |
Mr = 352.73 | Dx = 1.542 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
a = 14.4554 (4) Å | Cell parameters from 4621 reflections |
b = 8.5865 (2) Å | θ = 3.1–32.0° |
c = 24.8055 (8) Å | µ = 1.78 mm−1 |
β = 99.209 (3)° | T = 120 K |
V = 3039.22 (16) Å3 | Block, blue |
Z = 8 | 0.21 × 0.16 × 0.11 mm |
Agilent XCalibur diffractometer | 4251 reflections with I > 2σ(I) |
Detector resolution: 16.1511 pixels mm-1 | Rint = 0.040 |
ω scans | θmax = 32.6°, θmin = 2.8° |
Absorption correction: multi-scan (CrysAlisPro; Rigaku OD, 2018) | h = −20→21 |
Tmin = 0.549, Tmax = 1.000 | k = −12→11 |
15974 measured reflections | l = −37→37 |
5137 independent reflections |
Refinement on F2 | Primary atom site location: dual |
Least-squares matrix: full | Hydrogen site location: mixed |
R[F2 > 2σ(F2)] = 0.038 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.081 | w = 1/[σ2(Fo2) + (0.0199P)2 + 4.4488P] where P = (Fo2 + 2Fc2)/3 |
S = 1.13 | (Δ/σ)max = 0.001 |
5137 reflections | Δρmax = 0.54 e Å−3 |
178 parameters | Δρmin = −0.51 e Å−3 |
0 restraints |
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. |
x | y | z | Uiso*/Ueq | ||
Cu1 | 0.50986 (2) | 0.75598 (3) | 0.37062 (2) | 0.01272 (6) | |
Cl1 | 0.41953 (3) | 0.66088 (6) | 0.43059 (2) | 0.01703 (10) | |
Cl2 | 0.61677 (3) | 0.86629 (5) | 0.32152 (2) | 0.01706 (10) | |
O1 | 0.40656 (10) | 0.69534 (18) | 0.29006 (6) | 0.0192 (3) | |
H1 | 0.408 (2) | 0.738 (3) | 0.2640 (12) | 0.029* | |
N2 | 0.45788 (11) | 0.97058 (19) | 0.38001 (7) | 0.0145 (3) | |
N1 | 0.57721 (11) | 0.54847 (19) | 0.37032 (7) | 0.0149 (3) | |
C1 | 0.49779 (13) | 1.0690 (2) | 0.41912 (8) | 0.0141 (3) | |
C2 | 0.45939 (14) | 1.2154 (2) | 0.42581 (8) | 0.0168 (4) | |
H2 | 0.488544 | 1.282802 | 0.452631 | 0.020* | |
C3 | 0.64638 (14) | 0.5067 (2) | 0.41102 (9) | 0.0175 (4) | |
C4 | 0.58446 (14) | 1.0157 (2) | 0.45567 (8) | 0.0188 (4) | |
H4A | 0.571444 | 0.921107 | 0.473669 | 0.028* | |
H4B | 0.604355 | 1.094501 | 0.482496 | 0.028* | |
H4C | 0.633209 | 0.997353 | 0.434317 | 0.028* | |
C5 | 0.66783 (15) | 0.2646 (2) | 0.36638 (9) | 0.0220 (4) | |
H5 | 0.698699 | 0.170012 | 0.364995 | 0.026* | |
C6 | 0.69292 (14) | 0.3650 (2) | 0.40943 (9) | 0.0216 (4) | |
H6 | 0.740983 | 0.338329 | 0.437494 | 0.026* | |
C7 | 0.37914 (14) | 1.0160 (2) | 0.34693 (9) | 0.0201 (4) | |
H7 | 0.351990 | 0.948582 | 0.319564 | 0.024* | |
C8 | 0.55316 (15) | 0.4492 (2) | 0.32849 (8) | 0.0190 (4) | |
H8 | 0.505512 | 0.477838 | 0.300461 | 0.023* | |
C9 | 0.37781 (15) | 1.2600 (2) | 0.39241 (9) | 0.0192 (4) | |
H9 | 0.350701 | 1.356328 | 0.396982 | 0.023* | |
C10 | 0.59622 (16) | 0.3063 (2) | 0.32532 (9) | 0.0220 (4) | |
H10 | 0.577215 | 0.239722 | 0.296070 | 0.026* | |
C11 | 0.33724 (15) | 1.1589 (3) | 0.35209 (9) | 0.0223 (4) | |
H11 | 0.282686 | 1.186387 | 0.328834 | 0.027* | |
C12 | 0.32370 (15) | 0.6023 (3) | 0.28385 (9) | 0.0231 (4) | |
H12A | 0.326320 | 0.525448 | 0.256034 | 0.035* | |
H12B | 0.269827 | 0.667541 | 0.273541 | 0.035* | |
H12C | 0.319211 | 0.551434 | 0.317792 | 0.035* | |
C13 | 0.67215 (16) | 0.6175 (3) | 0.45740 (10) | 0.0271 (5) | |
H13A | 0.691508 | 0.714806 | 0.443729 | 0.041* | |
H13B | 0.722622 | 0.574607 | 0.482943 | 0.041* | |
H13C | 0.618872 | 0.634370 | 0.475334 | 0.041* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.01378 (11) | 0.01059 (11) | 0.01375 (11) | 0.00289 (8) | 0.00206 (8) | −0.00104 (8) |
Cl1 | 0.0200 (2) | 0.0157 (2) | 0.0161 (2) | 0.00216 (17) | 0.00497 (17) | 0.00003 (17) |
Cl2 | 0.0182 (2) | 0.0149 (2) | 0.0192 (2) | −0.00028 (16) | 0.00627 (17) | −0.00322 (17) |
O1 | 0.0226 (7) | 0.0190 (7) | 0.0152 (7) | −0.0020 (6) | 0.0008 (6) | 0.0024 (6) |
N2 | 0.0145 (7) | 0.0122 (7) | 0.0175 (8) | 0.0024 (6) | 0.0047 (6) | 0.0004 (6) |
N1 | 0.0152 (7) | 0.0133 (7) | 0.0168 (8) | 0.0020 (6) | 0.0045 (6) | −0.0011 (6) |
C1 | 0.0168 (8) | 0.0135 (8) | 0.0128 (8) | 0.0014 (7) | 0.0049 (7) | 0.0018 (7) |
C2 | 0.0226 (9) | 0.0128 (9) | 0.0165 (9) | 0.0015 (7) | 0.0075 (8) | −0.0011 (7) |
C3 | 0.0157 (9) | 0.0155 (9) | 0.0217 (10) | 0.0024 (7) | 0.0041 (7) | 0.0004 (8) |
C4 | 0.0216 (9) | 0.0175 (9) | 0.0164 (9) | 0.0042 (8) | 0.0005 (8) | −0.0029 (8) |
C5 | 0.0252 (10) | 0.0135 (9) | 0.0304 (11) | 0.0057 (8) | 0.0138 (9) | 0.0027 (8) |
C6 | 0.0186 (9) | 0.0196 (10) | 0.0264 (11) | 0.0077 (8) | 0.0030 (8) | 0.0034 (8) |
C7 | 0.0178 (9) | 0.0175 (9) | 0.0237 (10) | 0.0031 (7) | −0.0009 (8) | −0.0033 (8) |
C8 | 0.0235 (10) | 0.0190 (10) | 0.0154 (9) | 0.0031 (8) | 0.0055 (8) | −0.0020 (8) |
C9 | 0.0233 (10) | 0.0138 (9) | 0.0225 (10) | 0.0058 (7) | 0.0094 (8) | 0.0022 (8) |
C10 | 0.0293 (11) | 0.0163 (9) | 0.0222 (10) | 0.0021 (8) | 0.0101 (9) | −0.0044 (8) |
C11 | 0.0198 (9) | 0.0205 (10) | 0.0252 (11) | 0.0076 (8) | −0.0007 (8) | −0.0007 (8) |
C12 | 0.0202 (10) | 0.0289 (11) | 0.0202 (10) | 0.0001 (8) | 0.0033 (8) | −0.0023 (9) |
C13 | 0.0236 (10) | 0.0235 (11) | 0.0303 (12) | 0.0082 (9) | −0.0081 (9) | −0.0069 (9) |
Cu1—Cl1 | 2.2818 (5) | C4—H4C | 0.9600 |
Cu1—Cl2 | 2.3175 (5) | C5—H5 | 0.9300 |
Cu1—O1 | 2.3534 (15) | C5—C6 | 1.375 (3) |
Cu1—N2 | 2.0174 (16) | C5—C10 | 1.378 (3) |
Cu1—N1 | 2.0310 (16) | C6—H6 | 0.9300 |
O1—H1 | 0.75 (3) | C7—H7 | 0.9300 |
O1—C12 | 1.427 (3) | C7—C11 | 1.383 (3) |
N2—C1 | 1.345 (2) | C8—H8 | 0.9300 |
N2—C7 | 1.350 (3) | C8—C10 | 1.384 (3) |
N1—C3 | 1.351 (3) | C9—H9 | 0.9300 |
N1—C8 | 1.345 (3) | C9—C11 | 1.382 (3) |
C1—C2 | 1.395 (3) | C10—H10 | 0.9300 |
C1—C4 | 1.496 (3) | C11—H11 | 0.9300 |
C2—H2 | 0.9300 | C12—H12A | 0.9600 |
C2—C9 | 1.382 (3) | C12—H12B | 0.9600 |
C3—C6 | 1.394 (3) | C12—H12C | 0.9600 |
C3—C13 | 1.494 (3) | C13—H13A | 0.9600 |
C4—H4A | 0.9600 | C13—H13B | 0.9600 |
C4—H4B | 0.9600 | C13—H13C | 0.9600 |
Cl1—Cu1—Cl2 | 171.17 (2) | C6—C5—H5 | 120.5 |
Cl1—Cu1—O1 | 97.06 (4) | C6—C5—C10 | 118.99 (19) |
Cl2—Cu1—O1 | 91.73 (4) | C10—C5—H5 | 120.5 |
N2—Cu1—Cl1 | 89.37 (5) | C3—C6—H6 | 120.0 |
N2—Cu1—Cl2 | 88.82 (5) | C5—C6—C3 | 120.0 (2) |
N2—Cu1—O1 | 95.90 (6) | C5—C6—H6 | 120.0 |
N2—Cu1—N1 | 171.61 (7) | N2—C7—H7 | 118.7 |
N1—Cu1—Cl1 | 90.74 (5) | N2—C7—C11 | 122.6 (2) |
N1—Cu1—Cl2 | 89.79 (5) | C11—C7—H7 | 118.7 |
N1—Cu1—O1 | 92.42 (6) | N1—C8—H8 | 118.6 |
Cu1—O1—H1 | 121 (2) | N1—C8—C10 | 122.9 (2) |
C12—O1—Cu1 | 128.53 (13) | C10—C8—H8 | 118.6 |
C12—O1—H1 | 109 (2) | C2—C9—H9 | 120.6 |
C1—N2—Cu1 | 122.19 (13) | C2—C9—C11 | 118.84 (19) |
C1—N2—C7 | 118.63 (17) | C11—C9—H9 | 120.6 |
C7—N2—Cu1 | 119.16 (14) | C5—C10—C8 | 118.7 (2) |
C3—N1—Cu1 | 121.89 (13) | C5—C10—H10 | 120.7 |
C8—N1—Cu1 | 119.60 (13) | C8—C10—H10 | 120.7 |
C8—N1—C3 | 118.50 (17) | C7—C11—H11 | 120.6 |
N2—C1—C2 | 121.29 (18) | C9—C11—C7 | 118.87 (19) |
N2—C1—C4 | 117.75 (17) | C9—C11—H11 | 120.6 |
C2—C1—C4 | 120.96 (18) | O1—C12—H12A | 109.5 |
C1—C2—H2 | 120.1 | O1—C12—H12B | 109.5 |
C9—C2—C1 | 119.71 (19) | O1—C12—H12C | 109.5 |
C9—C2—H2 | 120.1 | H12A—C12—H12B | 109.5 |
N1—C3—C6 | 120.91 (19) | H12A—C12—H12C | 109.5 |
N1—C3—C13 | 118.02 (17) | H12B—C12—H12C | 109.5 |
C6—C3—C13 | 121.06 (19) | C3—C13—H13A | 109.5 |
C1—C4—H4A | 109.5 | C3—C13—H13B | 109.5 |
C1—C4—H4B | 109.5 | C3—C13—H13C | 109.5 |
C1—C4—H4C | 109.5 | H13A—C13—H13B | 109.5 |
H4A—C4—H4B | 109.5 | H13A—C13—H13C | 109.5 |
H4A—C4—H4C | 109.5 | H13B—C13—H13C | 109.5 |
H4B—C4—H4C | 109.5 | ||
Cu1—N2—C1—C2 | −178.36 (14) | C1—C2—C9—C11 | −1.5 (3) |
Cu1—N2—C1—C4 | 1.1 (2) | C2—C9—C11—C7 | 0.6 (3) |
Cu1—N2—C7—C11 | 177.53 (17) | C3—N1—C8—C10 | −0.1 (3) |
Cu1—N1—C3—C6 | −178.70 (15) | C4—C1—C2—C9 | −178.23 (18) |
Cu1—N1—C3—C13 | 0.6 (3) | C6—C5—C10—C8 | 1.1 (3) |
Cu1—N1—C8—C10 | 179.63 (16) | C7—N2—C1—C2 | 0.0 (3) |
N2—C1—C2—C9 | 1.2 (3) | C7—N2—C1—C4 | 179.42 (18) |
N2—C7—C11—C9 | 0.5 (3) | C8—N1—C3—C6 | 1.0 (3) |
N1—C3—C6—C5 | −0.9 (3) | C8—N1—C3—C13 | −179.70 (19) |
N1—C8—C10—C5 | −1.0 (3) | C10—C5—C6—C3 | −0.2 (3) |
C1—N2—C7—C11 | −0.9 (3) | C13—C3—C6—C5 | 179.8 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···Cl2i | 0.75 (3) | 2.37 (3) | 3.1033 (16) | 169 (3) |
C7—H7···O1 | 0.93 | 2.46 | 3.148 (3) | 130 |
C8—H8···O1 | 0.93 | 2.34 | 3.036 (3) | 131 |
C11—H11···Cl2ii | 0.93 | 2.83 | 3.624 (2) | 143 |
Symmetry codes: (i) −x+1, y, −z+1/2; (ii) x−1/2, y+1/2, z. |
Acknowledgements
The author thanks Professor G. C. Diaz de Delgado for her help and discussions on the crystallographic aspect of this work.
Funding information
Funding for this research was provided by: Indrashil University.
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