| Abstract |
The cationic (1,3,5-triazapentadiene)Pt-II complex [Pt\NH=C(N(CH2)(5))N(Ph)C(NH2)=NPh\(2)]Cl-2 ([1]Cl-2) was crystallized from four haloalkane solvents giving [1][Cl-2(CDCl3)(4)], [1][Cl-2(CHBr3)(4)], [1][Cl-2(CH2Cl2)(2)], and [1][Cl-2(C2H4Cl2)(2)] solvates that were studied by X-ray diffraction. In the crystal structures of [1][Cl-2(CDCl3)(4)] and [1][Cl-2(CHBr3)(4)], the Cl- ion interacts with two haloform molecules via C-D center dot center dot center dot Cl- and C-H center dot center dot center dot Cl- contacts, thus forming the negatively charged isostructural clusters [Cl(CDCl3)(2)](-) and [Cl(CHBr3)(2)](-). In the structures of [1][Cl-2(CH2Cl2)(2)] and [1][Cl-2(C2H4Cl2)(2)], cations [1](2+) are linked to a 3D-network by a system of H-bondings including one formed by each Cl- ion with CH2Cl2 or C2H4Cl2 molecules. The lengths and energies of these H-bonds in the chloride-haloalkane clusters were analyzed by DFT calculations (M06 functional) including AIM analysis. The crystal packing noticeably affected the geometry of the clusters, and energy of C-H center dot center dot center dot Cl- hydrogen bonds ranged from 1 to 6 kcal mol(-1). An exponential correlation (R-2 > 0.98) between the calculated Cl-center dot center dot center dot H distances and the energies of the corresponding contacts was found and used to calculate hydrogen bond energies from the experimental Cl-center dot center dot center dot H distances. Predicted energy values (3.3-3.9 kcal mol(-1) for the [Cl(CHCl3)(2)](-) cluster) are in a reasonable agreement with the energy of the Cl3C-H center dot center dot center dot Cl- bond estimated using ATRFTIR spectroscopy (2.7 kcal mol(-1)). |
