| Abstract |
Two previously reported 1,3,5,7,9-pentaazanona-1,3,6,8-tetraenate (PANT) chloride platinum(II) complexes [PtCl\HN=C(R)N=CN[C(Ph)=C(Ph)]C=NC(R)=NH\] (R = Bu-t 1, Ph 2) form solvates with halomethanes 1 center dot 11/4CH(2)Cl(2), 1 center dot 12/5CH(2)Br(2), and 2 center dot CHCl3. All these species feature novel complex-solvent heterotetrameric clusters, where the structural units are linked simultaneously by two C-X center dot center dot center dot Cl-Pt (X = Cl, Br) halogen and two C-H center dot center dot center dot Cl-Pt hydrogen bonds. The geometric parameters of these weak interactions were determined using single-crystal XRD, and the natures of the XBs and HBs in the clusters were studied for the isolated model systems (1)(2)center dot(CH2Cl2)(2), (1)(2)center dot(CH2Br2)(2), and (2)(2)center dot(CHCl3)(2) using DFT calculations and Bader s AIM analysis. The evaluated energies of the weak interactions are in the range 0.9-3.0 kcal mol(-1). The XBs and HBs in the reported clusters are cooperative. In the cases of (1)(2)center dot(CH2Cl2)(2) and (1)(2)center dot(CH2Br2)(2), the contribution of the HBs to the stabilization of the system is dominant, whereas for (2)(2)center dot(CHCl3)(2) contributions of both types of the non-covalent interactions are almost the same. Crystal packing and other forces such as, e.g. dipole-dipole interactions, also affect the formation of the clusters. |
