Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536813015456/lr2107sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536813015456/lr2107Isup2.hkl |
CCDC reference: 891184
Key indicators
- Single-crystal synchrotron study
- T = 98 K
- Mean (C-C) = 0.002 Å
- R factor = 0.030
- wR factor = 0.085
- Data-to-parameter ratio = 20.2
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) ..... 1 PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L= 0.600 24 PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF .... 4
Alert level G ABSMU01_ALERT_1_G Calculation of _exptl_absorpt_correction_mu not performed for this radiation type. PLAT005_ALERT_5_G No _iucr_refine_instructions_details in the CIF ? Do ! PLAT180_ALERT_4_G Check Cell Rounding: # of Values Ending with 0 = 4 PLAT230_ALERT_2_G Hirshfeld Test Diff for S2 -- C12 .. 7.1 su PLAT230_ALERT_2_G Hirshfeld Test Diff for S3 -- C11 .. 10.9 su PLAT230_ALERT_2_G Hirshfeld Test Diff for N5 -- C11 .. 6.7 su PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X) Cr1 -- N5 .. 5.3 su PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X) Cr1 -- N6 .. 6.2 su PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels .......... 4 PLAT793_ALERT_4_G The Model has Chirality at N1 (Verify) .... S PLAT793_ALERT_4_G The Model has Chirality at N2 (Verify) .... S PLAT793_ALERT_4_G The Model has Chirality at N3 (Verify) .... S PLAT793_ALERT_4_G The Model has Chirality at N4 (Verify) .... S PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L= 0.600 10 PLAT984_ALERT_1_G The Cr-f'= 0.338 Deviates from the B&C-Value 0.334
0 ALERT level A = Most likely a serious problem - resolve or explain 0 ALERT level B = A potentially serious problem, consider carefully 3 ALERT level C = Check. Ensure it is not caused by an omission or oversight 15 ALERT level G = General information/check it is not something unexpected 2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 5 ALERT type 2 Indicator that the structure model may be wrong or deficient 3 ALERT type 3 Indicator that the structure quality may be low 7 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check
The free ligand cyclam was purchased from Stream Chemicals and used as provided. All chemicals were reagent grade materials and used without further purification. The cis-[Cr(cyclam)(NCS)2]SCN was synthesized according to the literature (Ferguson & Tobe, 1970).
Non-hydrogen atoms were refined anisotropically; hydrogen atoms were first located in a difference map; N–H hydrogen atoms were freely refined and C–H hydrogen atoms were constrained to ride on the parent carbon atom, with C–H = 0.98 Å and C–H = 0.99 Å and Uiso(H) = 1.2Ueq(C) for methylene groups.
The cyclam (1,4,8,11-tetraazacyclotetradecane) ligand is moderately flexible structure, and can adopt both planer (trans) and folded (cis) configurations (Poon & Pun, 1980). There are five conformational trans isomers for the cyclam which differ in the chirality of the sec-NH centers. The trans-I, trans-II and trans-V configurations can fold to form cis-I, cis-II and cis-V isomers, respectively (Subhan et al., 2011). Furthermore, the NCS group is an ambidentate ligand because it can coordinate to a transition metal ion through the nitrogen (M-NCS), or the sulfur (M-SCN), or both (M-NCS-M).
In this communication, we report the structure of [Cr(cyclam)(NCS)2]SCN in order to determine the mode of bonding of the thiocyanate group and to verify geometrical assignment made on the basis of spectroscopic measurements (Poon & Pun, 1980; Choi & Park (2003).
Counter anionic species play a very important role in coordination chemistry. This is another example of a cis-[Cr(cyclam)2(NCS)2]+ but with different counter anion (Friesen et al., 1997). The structural analysis shows that there is only one crystallographically independent Cr(III) complex cation where the nitrogen atoms of cyclam ligand occupy four adjacent sites and the two N-bonded NCS groups coordinate to the chromium centre in cis arrangement. The cyclam adopts the folded cis-V configuration with six- and five-membered chelate rings in chair and gauche conformation, respectively. The same conformational arrangement has been found in cis-[Cr(cyclam)(ONO)2]NO2(Choi et al., 2004a). An ellipsoid plot (50% probability level) of the cis-[Cr(cyclam)(NCS)2]SCN, together with the atomic labelling, is depicted in Fig. 1.
The Cr—N(cyclam) distances of 2.0851 (14) and 2.0897 (14) Å are good agreement with the corresponding Cr—N distances found in [Cr(cyclam)(ox)]ClO4 (Choi et al., 2004b), [Cr(cyclam)(acac)](ClO4)2 (Subhan et al. , 2011) and trans-[Cr(cyclam)(nic-O)2]ClO4 (Choi, 2009). The mean Cr-NCS distance of 1.9957 (14) Å is close the value of the range 1.9827 (15)–1.9895 (16) Å found in trans-[Cr(Me2tn)2(NCS)2]SCN, but slightly longer than the 1.9698 (14) Å of Cr-ONO found in cis-[Cr(cyclam)(ONO)2]NO2 (Choi et al., 2004a). The folded angle of 97.11° in the cyclam is comparable to the corresponding angles of 98.55°, 97.03°, 95.09°, 94.51° and 92.8° in [Cr(cyclam)(ox)]ClO4, [Cr(cyclam)(acac)](ClO4)2, cis-[Cr(cyclam)(ONO)2]NO2, cis-[Cr(cyclam)(N3)2]ClO4 and cis-[Cr(cyclam)Cl2]Cl, respectively (Choi et al., 2004b; Subhan et al., 2011; Meyer et al., 1998; Forsellini et al., 1986). As usually observed, the five-membered chelate rings adopt a gauche, and six-membered ring is in the chair conformation. The average bond angles of five- and six-membered chelate rings around chromium(III) are the 83.13 (6) and 90.21 (6)°, respectively. The coordinated isothiocyanate ligands are almost linear with N—C—S angles of 179.69 (17)° and 178.83 (15)°. The uncoordinated NCS- anion also adopts a linear conformation and its N and S atoms participates in hydrogen bonds with the N—H groups of cyclam ligand. The C12—S2 and C13—S4 bond lengths [1.6232 (17) and 1.639 (2) Å] of are slightly shorter than the C11—S3 [1.6082 (17) Å] in the NCS- groups. It seems that the slight elongation of the distances are attributed to the weak H atoms bonds of both S2 and S3 atoms. Table 1 contains the distances and angles of hydrogen bonds. These hydrogen-bonded networks help to stabilize the crystal structure.
For the synthesis, see: Ferguson & Tobe (1970); For spectroscopic studies, see: Choi & Park (2003); Poon & Pun (1980). For related structures, see: Forsellini et al. (1986); Friesen et al. (1997) Meyer et al. (1998); Choi et al. (2004a,b, 2009); Subhan et al. (2011).
Data collection: ADSC Quantum-210 ADX (Arvai & Nielsen, 1983); cell refinement: HKL-3000 (Otwinowski & Minor, 1997); data reduction: HKL-3000 (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2007); software used to prepare material for publication: WinGX (Farrugia, 2012).
[Cr(NCS)2(C10H24N4)]NCS | F(000) = 89 |
Mr = 426.57 | Dx = 1.469 Mg m−3 |
Monoclinic, P21/c | Synchrotron radiation, λ = 0.740 Å |
a = 10.590 (2) Å | Cell parameters from 39021 reflections |
b = 7.6970 (15) Å | θ = 1.9–33.1° |
c = 23.750 (5) Å | µ = 1.03 mm−1 |
β = 94.70 (3)° | T = 98 K |
V = 1929.4 (7) Å3 | Block, pink |
Z = 4 | 0.01 × 0.01 × 0.01 mm |
ADSC Q210 CCD area-detector diffractometer | 3998 reflections with I > 2σ(I) |
Radiation source: PLSII 2D bending magnet | Rint = 0.038 |
ω scan | θmax = 29.5°, θmin = 2.0° |
Absorption correction: empirical (using intensity measurements) (HKL-3000 SCALEPACK; Otwinowski & Minor, 1997) | h = −14→14 |
Tmin = 0.988, Tmax = 0.989 | k = −10→10 |
16587 measured reflections | l = −31→31 |
4727 independent reflections |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.030 | w = 1/[σ2(Fo2) + (0.0543P)2 + 0.0369P]
where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.085 | (Δ/σ)max = 0.001 |
S = 1.07 | Δρmax = 0.38 e Å−3 |
4727 reflections | Δρmin = −0.46 e Å−3 |
234 parameters | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0149 (11) |
[Cr(NCS)2(C10H24N4)]NCS | V = 1929.4 (7) Å3 |
Mr = 426.57 | Z = 4 |
Monoclinic, P21/c | Synchrotron radiation, λ = 0.740 Å |
a = 10.590 (2) Å | µ = 1.03 mm−1 |
b = 7.6970 (15) Å | T = 98 K |
c = 23.750 (5) Å | 0.01 × 0.01 × 0.01 mm |
β = 94.70 (3)° |
ADSC Q210 CCD area-detector diffractometer | 4727 independent reflections |
Absorption correction: empirical (using intensity measurements) (HKL-3000 SCALEPACK; Otwinowski & Minor, 1997) | 3998 reflections with I > 2σ(I) |
Tmin = 0.988, Tmax = 0.989 | Rint = 0.038 |
16587 measured reflections |
R[F2 > 2σ(F2)] = 0.030 | 0 restraints |
wR(F2) = 0.085 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.38 e Å−3 |
4727 reflections | Δρmin = −0.46 e Å−3 |
234 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
x | y | z | Uiso*/Ueq | ||
Cr1 | 0.78572 (2) | 0.65230 (3) | 0.13425 (2) | 0.01445 (9) | |
S2 | 0.80594 (3) | 1.01716 (5) | 0.29372 (2) | 0.02043 (10) | |
S3 | 1.17137 (4) | 0.91514 (6) | 0.09132 (2) | 0.03337 (12) | |
N1 | 0.87142 (12) | 0.48585 (16) | 0.19523 (5) | 0.0176 (3) | |
H1N1 | 0.949 (2) | 0.521 (2) | 0.2008 (8) | 0.030 (5)* | |
N2 | 0.60770 (11) | 0.58345 (16) | 0.15912 (5) | 0.0158 (2) | |
H1N2 | 0.5895 (18) | 0.494 (3) | 0.1465 (8) | 0.026 (5)* | |
N3 | 0.80817 (12) | 0.44123 (17) | 0.08083 (5) | 0.0194 (3) | |
H1N3 | 0.7441 (18) | 0.378 (2) | 0.0769 (8) | 0.024 (5)* | |
N4 | 0.67930 (12) | 0.78077 (18) | 0.06965 (5) | 0.0193 (3) | |
H1N4 | 0.6773 (17) | 0.888 (2) | 0.0783 (8) | 0.024 (5)* | |
N5 | 0.95059 (12) | 0.74035 (17) | 0.11200 (5) | 0.0216 (3) | |
N6 | 0.78208 (12) | 0.85015 (16) | 0.18914 (5) | 0.0203 (3) | |
C1 | 0.82134 (14) | 0.4809 (2) | 0.25209 (6) | 0.0199 (3) | |
H1A | 0.8357 | 0.5954 | 0.2705 | 0.024* | |
H1B | 0.8694 | 0.3932 | 0.2756 | 0.024* | |
C2 | 0.68044 (14) | 0.4373 (2) | 0.25004 (6) | 0.0203 (3) | |
H2A | 0.6664 | 0.3245 | 0.2305 | 0.024* | |
H2B | 0.6569 | 0.4225 | 0.2892 | 0.024* | |
C3 | 0.59240 (14) | 0.5705 (2) | 0.22082 (6) | 0.0195 (3) | |
H3A | 0.5037 | 0.5387 | 0.2263 | 0.023* | |
H3B | 0.6094 | 0.6855 | 0.2385 | 0.023* | |
C4 | 0.88174 (15) | 0.30950 (19) | 0.17019 (7) | 0.0224 (3) | |
H4A | 0.8016 | 0.2449 | 0.1728 | 0.027* | |
H4B | 0.9509 | 0.2437 | 0.1911 | 0.027* | |
C5 | 0.90900 (15) | 0.3290 (2) | 0.10901 (7) | 0.0248 (3) | |
H5A | 0.9932 | 0.3830 | 0.1064 | 0.030* | |
H5B | 0.9089 | 0.2138 | 0.0905 | 0.030* | |
C6 | 0.51544 (14) | 0.7103 (2) | 0.13191 (6) | 0.0215 (3) | |
H6A | 0.5239 | 0.8239 | 0.1514 | 0.026* | |
H6B | 0.4278 | 0.6677 | 0.1341 | 0.026* | |
C7 | 0.54392 (14) | 0.7294 (2) | 0.07095 (6) | 0.0228 (3) | |
H7A | 0.5283 | 0.6180 | 0.0507 | 0.027* | |
H7B | 0.4884 | 0.8191 | 0.0521 | 0.027* | |
C8 | 0.83850 (16) | 0.4808 (2) | 0.02215 (6) | 0.0266 (3) | |
H8A | 0.8490 | 0.3703 | 0.0017 | 0.032* | |
H8B | 0.9201 | 0.5441 | 0.0235 | 0.032* | |
C9 | 0.73707 (17) | 0.5890 (2) | −0.01027 (7) | 0.0295 (4) | |
H9A | 0.7568 | 0.5952 | −0.0503 | 0.035* | |
H9B | 0.6548 | 0.5286 | −0.0093 | 0.035* | |
C10 | 0.72283 (16) | 0.7724 (2) | 0.01150 (6) | 0.0257 (3) | |
H10A | 0.8054 | 0.8326 | 0.0114 | 0.031* | |
H10B | 0.6614 | 0.8356 | −0.0147 | 0.031* | |
C11 | 1.04332 (14) | 0.81402 (19) | 0.10314 (6) | 0.0200 (3) | |
C12 | 0.79292 (13) | 0.92117 (18) | 0.23267 (6) | 0.0172 (3) | |
S4 | 0.56857 (4) | 0.72414 (6) | 0.36233 (2) | 0.03051 (12) | |
N7 | 0.37447 (15) | 0.65647 (19) | 0.43301 (7) | 0.0338 (3) | |
C13 | 0.45576 (15) | 0.68218 (19) | 0.40360 (7) | 0.0235 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cr1 | 0.01319 (12) | 0.01531 (13) | 0.01455 (13) | −0.00352 (8) | −0.00060 (8) | 0.00023 (8) |
S2 | 0.01916 (18) | 0.02155 (19) | 0.02016 (19) | −0.00004 (13) | −0.00094 (14) | −0.00355 (14) |
S3 | 0.0250 (2) | 0.0448 (3) | 0.0303 (2) | −0.01871 (19) | 0.00255 (17) | 0.00597 (19) |
N1 | 0.0142 (6) | 0.0178 (6) | 0.0205 (6) | −0.0020 (5) | −0.0012 (5) | 0.0014 (5) |
N2 | 0.0142 (6) | 0.0153 (6) | 0.0176 (6) | −0.0019 (5) | 0.0005 (5) | −0.0001 (5) |
N3 | 0.0170 (6) | 0.0210 (6) | 0.0205 (6) | −0.0036 (5) | 0.0031 (5) | −0.0031 (5) |
N4 | 0.0183 (6) | 0.0204 (6) | 0.0184 (6) | −0.0053 (5) | −0.0028 (5) | 0.0018 (5) |
N5 | 0.0183 (6) | 0.0244 (7) | 0.0218 (6) | −0.0068 (5) | 0.0002 (5) | 0.0017 (5) |
N6 | 0.0216 (6) | 0.0171 (6) | 0.0217 (6) | −0.0036 (5) | −0.0012 (5) | −0.0002 (5) |
C1 | 0.0212 (7) | 0.0209 (7) | 0.0171 (7) | −0.0012 (6) | −0.0019 (6) | 0.0035 (6) |
C2 | 0.0213 (7) | 0.0213 (7) | 0.0183 (7) | −0.0019 (6) | 0.0022 (6) | 0.0036 (6) |
C3 | 0.0176 (7) | 0.0223 (7) | 0.0190 (7) | −0.0020 (6) | 0.0045 (6) | −0.0001 (6) |
C4 | 0.0208 (7) | 0.0177 (7) | 0.0282 (8) | 0.0016 (6) | 0.0000 (6) | 0.0006 (6) |
C5 | 0.0219 (7) | 0.0231 (8) | 0.0298 (8) | 0.0023 (6) | 0.0042 (6) | −0.0043 (6) |
C6 | 0.0154 (7) | 0.0230 (7) | 0.0256 (8) | 0.0005 (6) | −0.0006 (6) | 0.0038 (6) |
C7 | 0.0172 (7) | 0.0275 (8) | 0.0228 (7) | −0.0041 (6) | −0.0045 (6) | 0.0043 (6) |
C8 | 0.0293 (8) | 0.0320 (9) | 0.0195 (7) | −0.0042 (7) | 0.0077 (6) | −0.0062 (6) |
C9 | 0.0340 (9) | 0.0378 (9) | 0.0167 (7) | −0.0073 (8) | 0.0013 (7) | −0.0040 (7) |
C10 | 0.0284 (8) | 0.0323 (9) | 0.0160 (7) | −0.0071 (7) | −0.0006 (6) | 0.0049 (6) |
C11 | 0.0211 (7) | 0.0234 (7) | 0.0150 (7) | −0.0028 (6) | −0.0019 (6) | 0.0004 (6) |
C12 | 0.0146 (6) | 0.0146 (6) | 0.0218 (7) | −0.0024 (5) | −0.0017 (6) | 0.0028 (5) |
S4 | 0.0347 (2) | 0.0333 (2) | 0.0235 (2) | 0.01233 (18) | 0.00211 (17) | 0.00132 (17) |
N7 | 0.0297 (8) | 0.0263 (7) | 0.0453 (9) | 0.0070 (6) | 0.0013 (7) | 0.0027 (6) |
C13 | 0.0260 (8) | 0.0160 (7) | 0.0267 (8) | 0.0081 (6) | −0.0087 (7) | −0.0027 (6) |
Cr1—N5 | 1.9846 (13) | C2—C3 | 1.515 (2) |
Cr1—N6 | 2.0071 (13) | C2—H2A | 0.9900 |
Cr1—N4 | 2.0781 (14) | C2—H2B | 0.9900 |
Cr1—N1 | 2.0849 (13) | C3—H3A | 0.9900 |
Cr1—N3 | 2.0868 (13) | C3—H3B | 0.9900 |
Cr1—N2 | 2.0895 (13) | C4—C5 | 1.512 (2) |
S2—C12 | 1.6231 (15) | C4—H4A | 0.9900 |
S3—C11 | 1.6081 (16) | C4—H4B | 0.9900 |
N1—C4 | 1.4895 (19) | C5—H5A | 0.9900 |
N1—C1 | 1.4913 (19) | C5—H5B | 0.9900 |
N1—H1N1 | 0.86 (2) | C6—C7 | 1.510 (2) |
N2—C6 | 1.4904 (19) | C6—H6A | 0.9900 |
N2—C3 | 1.4909 (18) | C6—H6B | 0.9900 |
N2—H1N2 | 0.77 (2) | C7—H7A | 0.9900 |
N3—C8 | 1.4871 (19) | C7—H7B | 0.9900 |
N3—C5 | 1.489 (2) | C8—C9 | 1.518 (2) |
N3—H1N3 | 0.834 (19) | C8—H8A | 0.9900 |
N4—C7 | 1.4901 (19) | C8—H8B | 0.9900 |
N4—C10 | 1.4928 (19) | C9—C10 | 1.515 (2) |
N4—H1N4 | 0.851 (19) | C9—H9A | 0.9900 |
N5—C11 | 1.168 (2) | C9—H9B | 0.9900 |
N6—C12 | 1.1666 (19) | C10—H10A | 0.9900 |
C1—C2 | 1.526 (2) | C10—H10B | 0.9900 |
C1—H1A | 0.9900 | S4—C13 | 1.6384 (19) |
C1—H1B | 0.9900 | N7—C13 | 1.169 (2) |
N5—Cr1—N6 | 88.74 (6) | H2A—C2—H2B | 107.5 |
N5—Cr1—N4 | 94.39 (5) | N2—C3—C2 | 112.52 (12) |
N6—Cr1—N4 | 94.61 (6) | N2—C3—H3A | 109.1 |
N5—Cr1—N1 | 93.01 (5) | C2—C3—H3A | 109.1 |
N6—Cr1—N1 | 92.61 (5) | N2—C3—H3B | 109.1 |
N4—Cr1—N1 | 169.77 (5) | C2—C3—H3B | 109.1 |
N5—Cr1—N3 | 87.56 (6) | H3A—C3—H3B | 107.8 |
N6—Cr1—N3 | 174.14 (5) | N1—C4—C5 | 108.61 (12) |
N4—Cr1—N3 | 90.20 (5) | N1—C4—H4A | 110.0 |
N1—Cr1—N3 | 83.06 (5) | C5—C4—H4A | 110.0 |
N5—Cr1—N2 | 174.70 (5) | N1—C4—H4B | 110.0 |
N6—Cr1—N2 | 86.73 (5) | C5—C4—H4B | 110.0 |
N4—Cr1—N2 | 83.23 (5) | H4A—C4—H4B | 108.3 |
N1—Cr1—N2 | 89.96 (5) | N3—C5—C4 | 107.65 (12) |
N3—Cr1—N2 | 97.17 (5) | N3—C5—H5A | 110.2 |
C4—N1—C1 | 112.42 (11) | C4—C5—H5A | 110.2 |
C4—N1—Cr1 | 108.95 (9) | N3—C5—H5B | 110.2 |
C1—N1—Cr1 | 118.54 (9) | C4—C5—H5B | 110.2 |
C4—N1—H1N1 | 104.3 (13) | H5A—C5—H5B | 108.5 |
C1—N1—H1N1 | 105.8 (13) | N2—C6—C7 | 107.70 (12) |
Cr1—N1—H1N1 | 105.6 (13) | N2—C6—H6A | 110.2 |
C6—N2—C3 | 110.46 (12) | C7—C6—H6A | 110.2 |
C6—N2—Cr1 | 106.62 (9) | N2—C6—H6B | 110.2 |
C3—N2—Cr1 | 117.91 (9) | C7—C6—H6B | 110.2 |
C6—N2—H1N2 | 106.5 (14) | H6A—C6—H6B | 108.5 |
C3—N2—H1N2 | 106.1 (14) | N4—C7—C6 | 108.29 (12) |
Cr1—N2—H1N2 | 108.7 (14) | N4—C7—H7A | 110.0 |
C8—N3—C5 | 109.76 (12) | C6—C7—H7A | 110.0 |
C8—N3—Cr1 | 117.03 (10) | N4—C7—H7B | 110.0 |
C5—N3—Cr1 | 106.96 (10) | C6—C7—H7B | 110.0 |
C8—N3—H1N3 | 104.5 (13) | H7A—C7—H7B | 108.4 |
C5—N3—H1N3 | 105.0 (12) | N3—C8—C9 | 112.93 (13) |
Cr1—N3—H1N3 | 113.0 (13) | N3—C8—H8A | 109.0 |
C7—N4—C10 | 112.23 (12) | C9—C8—H8A | 109.0 |
C7—N4—Cr1 | 108.83 (9) | N3—C8—H8B | 109.0 |
C10—N4—Cr1 | 118.20 (10) | C9—C8—H8B | 109.0 |
C7—N4—H1N4 | 102.1 (12) | H8A—C8—H8B | 107.8 |
C10—N4—H1N4 | 106.4 (12) | C10—C9—C8 | 115.10 (13) |
Cr1—N4—H1N4 | 107.8 (12) | C10—C9—H9A | 108.5 |
C11—N5—Cr1 | 170.02 (13) | C8—C9—H9A | 108.5 |
C12—N6—Cr1 | 157.72 (12) | C10—C9—H9B | 108.5 |
N1—C1—C2 | 113.34 (12) | C8—C9—H9B | 108.5 |
N1—C1—H1A | 108.9 | H9A—C9—H9B | 107.5 |
C2—C1—H1A | 108.9 | N4—C10—C9 | 113.77 (13) |
N1—C1—H1B | 108.9 | N4—C10—H10A | 108.8 |
C2—C1—H1B | 108.9 | C9—C10—H10A | 108.8 |
H1A—C1—H1B | 107.7 | N4—C10—H10B | 108.8 |
C3—C2—C1 | 115.42 (12) | C9—C10—H10B | 108.8 |
C3—C2—H2A | 108.4 | H10A—C10—H10B | 107.7 |
C1—C2—H2A | 108.4 | N5—C11—S3 | 179.66 (15) |
C3—C2—H2B | 108.4 | N6—C12—S2 | 178.82 (14) |
C1—C2—H2B | 108.4 | N7—C13—S4 | 178.35 (14) |
C4—N1—C1—C2 | −72.13 (15) | C3—N2—C6—C7 | 174.88 (12) |
Cr1—N1—C1—C2 | 56.50 (15) | Cr1—N2—C6—C7 | 45.63 (13) |
N1—C1—C2—C3 | −64.97 (17) | C10—N4—C7—C6 | 169.85 (13) |
C6—N2—C3—C2 | 177.56 (12) | Cr1—N4—C7—C6 | 37.10 (15) |
Cr1—N2—C3—C2 | −59.54 (15) | N2—C6—C7—N4 | −55.65 (16) |
C1—C2—C3—N2 | 66.51 (17) | C5—N3—C8—C9 | 177.66 (13) |
C1—N1—C4—C5 | 169.43 (12) | Cr1—N3—C8—C9 | −60.26 (16) |
Cr1—N1—C4—C5 | 35.94 (14) | N3—C8—C9—C10 | 66.73 (19) |
C8—N3—C5—C4 | 173.69 (12) | C7—N4—C10—C9 | −71.42 (17) |
Cr1—N3—C5—C4 | 45.79 (14) | Cr1—N4—C10—C9 | 56.52 (16) |
N1—C4—C5—N3 | −54.89 (16) | C8—C9—C10—N4 | −64.47 (18) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N1···S2i | 0.86 (2) | 2.59 (2) | 3.4138 (15) | 160.1 (17) |
N2—H1N2···S4ii | 0.77 (2) | 2.66 (2) | 3.3521 (14) | 149.8 (18) |
N3—H1N3···N7ii | 0.834 (19) | 2.119 (19) | 2.9238 (19) | 162.0 (17) |
N4—H1N4···N7iii | 0.851 (19) | 2.150 (19) | 2.947 (2) | 155.9 (17) |
Symmetry codes: (i) −x+2, y−1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) −x+1, y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | [Cr(NCS)2(C10H24N4)]NCS |
Mr | 426.57 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 98 |
a, b, c (Å) | 10.590 (2), 7.6970 (15), 23.750 (5) |
β (°) | 94.70 (3) |
V (Å3) | 1929.4 (7) |
Z | 4 |
Radiation type | Synchrotron, λ = 0.740 Å |
µ (mm−1) | 1.03 |
Crystal size (mm) | 0.01 × 0.01 × 0.01 |
Data collection | |
Diffractometer | ADSC Q210 CCD area-detector |
Absorption correction | Empirical (using intensity measurements) (HKL-3000 SCALEPACK; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.988, 0.989 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 16587, 4727, 3998 |
Rint | 0.038 |
(sin θ/λ)max (Å−1) | 0.665 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.085, 1.07 |
No. of reflections | 4727 |
No. of parameters | 234 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.38, −0.46 |
Computer programs: ADSC Quantum-210 ADX (Arvai & Nielsen, 1983), HKL-3000 (Otwinowski & Minor, 1997), SHELXS2013 (Sheldrick, 2008), SHELXL2013 (Sheldrick, 2008), DIAMOND (Brandenburg, 2007), WinGX (Farrugia, 2012).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N1···S2i | 0.86 (2) | 2.59 (2) | 3.4138 (15) | 160.1 (17) |
N2—H1N2···S4ii | 0.77 (2) | 2.66 (2) | 3.3521 (14) | 149.8 (18) |
N3—H1N3···N7ii | 0.834 (19) | 2.119 (19) | 2.9238 (19) | 162.0 (17) |
N4—H1N4···N7iii | 0.851 (19) | 2.150 (19) | 2.947 (2) | 155.9 (17) |
Symmetry codes: (i) −x+2, y−1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) −x+1, y+1/2, −z+1/2. |
The cyclam (1,4,8,11-tetraazacyclotetradecane) ligand is moderately flexible structure, and can adopt both planer (trans) and folded (cis) configurations (Poon & Pun, 1980). There are five conformational trans isomers for the cyclam which differ in the chirality of the sec-NH centers. The trans-I, trans-II and trans-V configurations can fold to form cis-I, cis-II and cis-V isomers, respectively (Subhan et al., 2011). Furthermore, the NCS group is an ambidentate ligand because it can coordinate to a transition metal ion through the nitrogen (M-NCS), or the sulfur (M-SCN), or both (M-NCS-M).
In this communication, we report the structure of [Cr(cyclam)(NCS)2]SCN in order to determine the mode of bonding of the thiocyanate group and to verify geometrical assignment made on the basis of spectroscopic measurements (Poon & Pun, 1980; Choi & Park (2003).
Counter anionic species play a very important role in coordination chemistry. This is another example of a cis-[Cr(cyclam)2(NCS)2]+ but with different counter anion (Friesen et al., 1997). The structural analysis shows that there is only one crystallographically independent Cr(III) complex cation where the nitrogen atoms of cyclam ligand occupy four adjacent sites and the two N-bonded NCS groups coordinate to the chromium centre in cis arrangement. The cyclam adopts the folded cis-V configuration with six- and five-membered chelate rings in chair and gauche conformation, respectively. The same conformational arrangement has been found in cis-[Cr(cyclam)(ONO)2]NO2(Choi et al., 2004a). An ellipsoid plot (50% probability level) of the cis-[Cr(cyclam)(NCS)2]SCN, together with the atomic labelling, is depicted in Fig. 1.
The Cr—N(cyclam) distances of 2.0851 (14) and 2.0897 (14) Å are good agreement with the corresponding Cr—N distances found in [Cr(cyclam)(ox)]ClO4 (Choi et al., 2004b), [Cr(cyclam)(acac)](ClO4)2 (Subhan et al. , 2011) and trans-[Cr(cyclam)(nic-O)2]ClO4 (Choi, 2009). The mean Cr-NCS distance of 1.9957 (14) Å is close the value of the range 1.9827 (15)–1.9895 (16) Å found in trans-[Cr(Me2tn)2(NCS)2]SCN, but slightly longer than the 1.9698 (14) Å of Cr-ONO found in cis-[Cr(cyclam)(ONO)2]NO2 (Choi et al., 2004a). The folded angle of 97.11° in the cyclam is comparable to the corresponding angles of 98.55°, 97.03°, 95.09°, 94.51° and 92.8° in [Cr(cyclam)(ox)]ClO4, [Cr(cyclam)(acac)](ClO4)2, cis-[Cr(cyclam)(ONO)2]NO2, cis-[Cr(cyclam)(N3)2]ClO4 and cis-[Cr(cyclam)Cl2]Cl, respectively (Choi et al., 2004b; Subhan et al., 2011; Meyer et al., 1998; Forsellini et al., 1986). As usually observed, the five-membered chelate rings adopt a gauche, and six-membered ring is in the chair conformation. The average bond angles of five- and six-membered chelate rings around chromium(III) are the 83.13 (6) and 90.21 (6)°, respectively. The coordinated isothiocyanate ligands are almost linear with N—C—S angles of 179.69 (17)° and 178.83 (15)°. The uncoordinated NCS- anion also adopts a linear conformation and its N and S atoms participates in hydrogen bonds with the N—H groups of cyclam ligand. The C12—S2 and C13—S4 bond lengths [1.6232 (17) and 1.639 (2) Å] of are slightly shorter than the C11—S3 [1.6082 (17) Å] in the NCS- groups. It seems that the slight elongation of the distances are attributed to the weak H atoms bonds of both S2 and S3 atoms. Table 1 contains the distances and angles of hydrogen bonds. These hydrogen-bonded networks help to stabilize the crystal structure.