| Abstract |
The reaction of cis-[PdCl2(CNCy)(2)] (1) with thiazol-2-amines (2-10) leads to the C,N-chelated diaminocarbene-like complexes [PdCl\C(N(H)4,5-R-2-thiazol-2-yl)NHCy](CNCy)] (11-14; 82-91\%) in the case of 4,S-R-2-thiazol-2-amines (R, R = H, H (2), Me, Me (3),-(CH2)(4)- (4)) and benzothiazol-2-amine (5) or gives the diaminocarbene species cis[PdCl2\C(N(H)Cy)N(H)4-R-thiazol-2-yl\(CNCy)] (15-19; 73-93\%) for the reaction with 4-aryl-substituted thiazol-2-amines (R = Ph (6), 4-MeC6H4 (7), 4-FC6H4 (8), 4-ClC6H4 (9), 3,4-F2C6H3 (10)). Inspection of the single-crystal X-ray diffraction data for 15-17 and 19 suggests that the structures of all these species exhibit previously unrecognized bifurcated chalcogen-hydrogen bonding mu Cl-(S,Cl-N-H) and also Pd-II center dot center dot center dot Pd-II metallophilic interactions. These noncovalent interactions collectively connect two symmetrically located molecules of 15-17 and 19, resulting in their solid-state dimerization. The existence of the mu Cl-(S,Cl-N-H) system and its strength (6-9 kcal/mol) were additionally verified/estimated by a Hirshfeld surface analysis and DFT calculations combined with a topological analysis of the electron density distribution within the formalism of Bader s theory (AIM method) and NBO analysis. The observed noncovalent interactions are jointly responsible for the dimerization of 15-19 not only in the solid phase but also in CHCl3 solutions, as predicted theoretically by DFT calculations and confirmed experimentally by FTIR, HRESI-MS, H-1 NMR, and diffusion coefficient NMR measurements. Available CCDC data were processed under the new moiety angle, and the observed mu Cl-(S,Cl-N-H) systems were classified accordingly to E (E = N, O, C) type atoms. |
