Bis(μ2-N-methyl-N-phenyl­di­thio­carbamato)-κ3S,S′:S;κ3S:S,S′-bis­­[(N-methyl-N-phenyl­di­thio­carbamato-κ2S,S′)cadmium]: crystal structure and Hirshfeld surface analysis

The structural chemistry of the binary zinc-triad (group 12) di­thio­carbamates (−S2CNRR′)2 (R/R′ = alk­yl/aryl), along with related 1,1-di­thiol­ate ligands, i.e. di­thio­phosphates [−S2P(OR)2] and di­thio­carbonates (xanthates; −S2COR), have long attracted the attention of structural chemists owing to their diversity of structures/supra­molecular association patterns in the solid state (Cox & Tiekink, 1997[Cox, M. J. & Tiekink, E. R. T. (1997). Rev. Inorg. Chem. 17, 1-23.]; Tiekink, 2003[Tiekink, E. R. T. (2003). CrystEngComm, 5, 101-113.]). The common structural motif adopted by all elements is one that features two chelating ligands and two tridentate ligands (chelating one metal atom and simultaneously bridging to a second), leading, usually, to a centrosymmetric binuclear mol­ecule. Indeed, most zinc di­thio­carbamate structures adopt this motif, but when the R/R′ are bulky, a mononuclear species with tetrahedrally coordinated zinc atoms is found; significantly greater structural variety has been noted for the binary zinc di­thio­phosphates and xanthates (Lai et al., 2002[Lai, C. S., Lim, Y. X., Yap, T. C. & Tiekink, E. R. T. (2002). CrystEngComm, 4, 596-600.]; Tan et al., 2015[Tan, Y. S., Ooi, K. K., Ang, K. P., Akim, A. M., Cheah, Y.-K., Halim, S. N. A., Seng, H.-L. & Tiekink, E. R. T. (2015). J. Inorg. Biochem. 150, 48-62.]). More diversity in structural motifs is noted in the binary cadmium di­thio­carbamates with the recent observation of linear polymeric forms with hexa­coordinated cadmium atoms (Tan et al., 2013[Tan, Y. S., Sudlow, A. L., Molloy, K. C., Morishima, Y., Fujisawa, K., Jackson, W. J., Henderson, W., Halim, S. N., Bt, A., Ng, S. W. & Tiekink, E. R. T. (2013). Cryst. Growth Des. 13, 3046-3056.], 2016[Tan, Y. S., Halim, S. N. A. & Tiekink, E. R. T. (2016). Z. Kristallogr. 231, 113-126.]; Ferreira et al., 2016[Ferreira, I. P., de Lima, G. M., Paniago, E. B., Pinheiro, C. B., Wardell, J. L. & Wardell, S. M. S. V. (2016). Inorg. Chim. Acta, 441, 137-145.]). Systematic studies indicated solvent-mediated transformations between polymeric and binuclear structural motifs, with the latter being the thermodynamically more stable (Tan et al., 2013[Tan, Y. S., Sudlow, A. L., Molloy, K. C., Morishima, Y., Fujisawa, K., Jackson, W. J., Henderson, W., Halim, S. N., Bt, A., Ng, S. W. & Tiekink, E. R. T. (2013). Cryst. Growth Des. 13, 3046-3056.], 2016[Tan, Y. S., Halim, S. N. A. & Tiekink, E. R. T. (2016). Z. Kristallogr. 231, 113-126.]). The greatest structural diversity among the zinc-triad di­thio­carbamates is found for the binary mercury compounds, where mononuclear, binuclear and polymeric structures have been observed, as summarized very recently (Jotani et al., 2016[Jotani, M. M., Poplaukhin, P., Arman, H. D. & Tiekink, E. R. T. (2016). Acta Cryst. E72, 1085-1092.]). Complementing the structural motifs already mentioned for zinc and cadmium is a trinuclear species, {Hg[S2CN(tetra­hydro­quinoline)]2}3 (Rajput et al., 2014[Rajput, G., Yadav, M. K., Thakur, T. S., Drew, M. G. B. & Singh, N. (2014). Polyhedron, 69, 225-233.]), with the central HgII atom being hexa­coordinated, as in the polymeric form, and the peripheral HgII atoms being coordinated as in the binuclear form, indicating the possibility that this is an inter­mediate metastable form in the crystallization of this compound. In light of the above, when crystals of the title compound became available, namely {Cd[S2CN(Me)Ph]2}2, (I)[link], its crystal and mol­ecular structures were studied, along with an evaluation of the supra­molecular association in the crystal through an analysis of the Hirshfeld surface.