Formation of Heterobimetallic Complexes by Addition of d 10 -Metal Ions to [(Me 3 P) x M(2-C 6 F 4 PPh 2 ) 2 ] ( x = 1, 2; M = Ni and Pt): A Synthetic and Computational Study of Metallophilic Interactions.

Treatment of the bis(chelate) complexes trans -[M(κ 2 -2-C 6 F 4 PPh 2 ) 2 ] ( trans - 1M ; M = Ni, Pt) and cis -[Pt(κ 2 -2-C 6 F 4 PPh 2 ) 2 ] ( cis - 1Pt ) with equimolar amounts or excess of PMe 3 solution gave complexes of the type [(Me 3 P) x M(2-C 6 F 4 PPh 2 ) 2 ] ( x = 2: 2M a , 2M b x = 1: 3M a , 3M b ; M = Ni, Pt). The reactivity of complexes of the type 2M and 3M toward monovalent coinage metal ions (M' = Cu, Ag, Au) was investigated next to the reaction of 1M toward [AuCl(PMe 3 )]. Four different complex types [(Me 3 P) 2 M(μ-2-C 6 F 4 PPh 2 ) 2 M'Cl] ( 5MM' ; M = Ni, Pt; M' = Cu, Ag, Au), [(Me 3 P)M(κ 2 -2-C 6 F 4 PPh 2 )(μ-2-C 6 F 4 PPh 2 )M'Cl] x ( x = 1: 6MM' ; M = Pt; M' = Cu, Au; x = 2: 6PtAg ), head-to-tail-[(Me 3 P)ClM(μ-2-C 6 F 4 PPh 2 ) 2 M'] ( 7MM' ; M = Ni, Pt; M' = Au), and head-to-head-[(Me 3 P)ClM(μ-2-C 6 F 4 PPh 2 ) 2 M'] ( 8MM' ; M = Ni, Pt; M' = Cu, Ag, Au) were observed. Single-crystal X-ray analyses of complexes 5 - 8 revealed short metal-metal separations (2.7124(3)-3.3287(7) Å), suggestive of attractive metal-metal interactions. Quantum chemical calculations (atoms in molecules (AIM), electron localization function (ELF), non-covalent interaction (NCI), and natural bond orbital (NBO)) gave theoretical support that the interaction characteristics reach from a pure attractive non-covalent to an electron-shared (covalent) character.