Crystal structure of bis(acetonitrile)

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Crystal structure of bis(acetonitrile)hexacarbonyldi-m2-chlorido dirhenium(I) ... tron density (HFIX 137 in the SHELX program suite [6]), with. Uiso(H) set to ...
Z. Kristallogr. NCS 229 (2014) 355-356 / DOI 10.1515/ncrs-2014-0184

355

© 2014 by Walter de Gruyter Berlin/Boston

Crystal structure of bis(acetonitrile)hexacarbonyldi-$2-chlorido dirhenium(I), C10H6Cl2N2O6Re2 Janvier Mukiza, Thomas I. A. Gerber, Eric C. Hosten and Richard Betz* Nelson Mandela Metropolitan University, Summerstrand Campus, Department of Chemistry, University Way, Summerstrand, PO Box 77000, Port Elizabeth 6031, South Africa Received May 19, 2014, accepted September 18, 2014, available online September 26, 2014, CCDC no. 1267/4172

tron density (HFIX 137 in the SHELX program suite [6]), with Uiso(H) set to 1.5Ueq(C).

Abstract C10H6Cl2N2O6Re2, triclinic, P1 (no. 2), a = 6.8578(3) Å, b = 6.8931(3) Å, c = 8.8860(4) Å, & = 103.700(2)°, % = 99.354(2)°, ! = 94.067(2)°, V = 400.1 Å3, Z = 1, Rgt(F) = 0.0176, wRref(F2) = 0.0448, T = 200 K. Table 1. Data collection and handling. Crystal: Wavelength: $: Diffractometer, scan mode: 2#max: N(hkl)measured, N(hkl)unique: Criterion for Iobs, N(hkl)gt: N(param)refined: Programs:

colourless rods, size 0.05#0.10#0.19 mm Mo K! radiation (0.71073 Å) 154.75 cm"1 Bruker APEX-II CCD, ( and ' 56.68° 7113, 1983 Iobs > 2 "(Iobs), 1882 101 SHELX, WinGX, MERCURY, PLATON [4–7]

Source of material The compound was obtained upon heating Re(CO)5Cl in a mixture of toluene, dichloromethane, methanol and acetonitrile. Crystals suitable for the diffraction study were obtained upon free evaporation of the reaction batch at room temperature. Experimental details The H atoms of the methyl group were allowed to rotate with a fixed angle around the C–C bond to best fit the experimental elec-

Discussion Next to cardiovascular diseases, cancer has become one of the main fatal diseases in industrialized countries. Apart from classical surgery, chemo- and radiotherapeutic treatments have entered the arsenal of possible cures for certain types of cancer. All methods, however, suffer from their own set of problematic side-effects and, as a consequence, the development of radiopharmaceuticals – combining the advantages of chemotherapy as well as radiation methods while at the same time avoiding their unique respective undesired side-effects – has been a topic of research [1, 2]. Tailoring and fine-tuning of the envisioned radiopharmaceuticals' properties such as lipophilicity and, in particular, inertness is of paramount importance with respect to possible future in vivo applications in contemporary medicine and requires sound knowledge about structural parameters of the ligands applied if a more heuristic approach in the synthesis is to triumph over pure trial-and-error as it is encountered in this specific field of coordination chemistry up to the present day. In continuation of our investigation of rhenium-based coordination compounds that might serve as radiopharmaceuticals, the title compound was accidentially obtained as a decomposition product. The title compound is a dinuclear centrosymmetric rhenium(I) coordination compound. The asymmetric unit contains one half of the title complex. The rhenium atoms are hexacoordinated. The respective octahedral coordination geometry is constructed by three carbonyl ligands in fac configuration, an acetonitrile ligand, and two $2-bridging chlorido ligands. The asymmetric unit appears as a square pyramid with one of the carbonyl ligands as the apical ligand. The basal plane is nearly planar (r.m.s. of all fitted nonhydrogen atoms = 0.0202 Å) and shows the rhenium atom displaced by 0.050(1) Å from the latter. The angles enclosed by ligands in trans orientation over the rhenium atom deviate only slightly from linearity with values of 176.48(12)°, 176.50(11)° and 176.57(11)°, respectively. The central Re–Cl–Re–Cl pattern is a parallelogram with angles of 81.88(3)° and 98.12(3)°. The obtuse angle can be found at the chlorido ligands. The Re–Cl bond length was measured at 2.5187(9) Å. In comparison to values reported for other compounds featuring the same central Re2Cl2 motif and whose structural data has been deposited with the Cambridge Structural Database [3], it is found that the Re–Cl bond length in the title compound is longer than the most common values reported.

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* Correspondence author (e-mail: [email protected])

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C10H6Cl2N2O6Re2

Table 2. Atomic coordinates and displacement parameters (in Å2).

Table 2. continued.

Atom

Site

x

y

z

Uiso

Atom

Site

x

y

z

Uiso

H(5A) H(5B)

2i 2i

0.6328 0.4567

0.1781 0.0244

0.7504 0.7677

0.057 0.057

H(5C)

2i

0.4774

0.2562

0.8608

0.057

Table 3. Atomic coordinates and displacement parameters (in Å2). Atom

Site

Re(1) Cl(1) O(1) O(2) O(3) N(1) C(1) C(2) C(3) C(4) C(5)

2i 2i 2i 2i 2i 2i 2i 2i 2i 2i 2i

x 0.08770(2) 0.1778(1) "0.1830(4) "0.0332(5) 0.4246(4) 0.2695(5) "0.0832(5) 0.0121(6) 0.2978(5) 0.3694(7) 0.4937(7)

y 0.31789(2) 0.6741(1) 0.4430(5) "0.1157(4) 0.3162(5) 0.2433(5) 0.3976(6) 0.0465(6) 0.3219(5) 0.2044(6) 0.1625(7)

z

U11

U22

U33

0.33452(1) 0.4995(1) 0.0722(4) 0.1476(4) 0.1497(4) 0.5270(4) 0.1696(4) 0.2202(4) 0.2203(4) 0.6330(5) 0.7631(5)

0.01996(8) 0.0262(4) 0.029(1) 0.057(2) 0.031(2) 0.025(2) 0.020(2) 0.030(2) 0.026(2) 0.032(2) 0.036(2)

0.02109(8) 0.0244(4) 0.045(2) 0.026(1) 0.056(2) 0.032(2) 0.028(2) 0.027(2) 0.027(2) 0.033(2) 0.050(3)

0.01438(8) 0.0226(4) 0.029(2) 0.040(2) 0.036(2) 0.021(2) 0.022(2) 0.023(2) 0.023(2) 0.024(2) 0.028(2)

Acknowledgments. The authors thank Mr Homer Martinez Castillo for helpful discussions.

References 1. Yumata, N. C.; Habarurema, G.; Mukiza, J.; Gerber, T. I. A.; Hosten, E.; Taherkhani, F.; Nahali, M.:Rhenium complexes of di-2-pyridyl ketone, 2benzoylpyridine and 2-hydroxybenzophenone: A structural and theoretical study.Polyhedron 62 (2013) 89–103. 2. Potgieter, K. C.; Gerber, T. I. A.; Betz, R.; Rhyman, L.; Ramasami, P.: Structural and DFT/TD-DFT investigation of tris(bidentate) complexes of rhenium(III) synthesized from the cis-[ReO2]+ core and benzenethiol derivatives. Polyhedron. 59 (2013) 91–100.

U12 0.00282(5) "0.0029(3) 0.005(1) "0.001(1) 0.009(1) 0.006(1) "0.000(1) 0.006(1) 0.007(1) 0.004(2) 0.011(2)

U13 0.00367(5) 0.0092(3) "0.003(1) 0.011(2) 0.017(1) 0.005(1) 0.006(1) 0.008(1) 0.003(1) 0.009(2) "0.001(2)

U23 0.00268(5) 0.0003(3) 0.017(1) "0.004(1) 0.015(1) 0.006(1) 0.003(1) 0.007(1) 0.005(1) "0.005(2) 0.014(2)

3. Allen, F. H.: The Cambridge Structural Database: a quarter of a million crystal structures and rising. Acta Crystallogr. B58 (2002) 380–388. 4. Sheldrick, G. M.: A short history of SHELX. Acta Crystallogr. A64 (2008) 112–122. 5. Farrugia, L. J.: WinGX and ORTEP for Windows: an update. J. Appl. Crystallogr. 45 (2012) 849–854. 6. Macrae, C. F.; Bruno, I. J.; Chisholm, J. A.; Edgington, P. R.; McCabe, P.; Pidcock, E.; Rodriguez-Monge, L.; Taylor, R.; van de Streek, J.; Wood, P.A.: Mercury CSD 2.0 – new features for the visualization and investigation of crystal structures. J. Appl. Crystallogr. 41 (2008) 466–470. 7. Spek, A. L.: Structure validation in chemical crystallography. Acta Crystallogr. D65 (2009) 148–155.

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