Isothiocyanato complexes of rhenium III. Synthesis and characterization of [ReN(NCS) 2(Ph 3P) 2] and [ReN(NCS) 2(CH 3CN)(Ph 3P) 2]. X-ray crystal structure of [ReN(NCS) 2(CH 3CN)(Ph 3P) 2]·CH 3CN

Abstract

Novel rhenium isothiocyanato complexes have been prepared by ligand exchange procedures starting from [ReNCl 2(Ph 3P) 2] and KSCN. The reaction with KSCN yields the rhenium(V) nitrido complex [ReN(NCS) 2(Ph 3P) 2]. [ReN(NCS) 2(CH 3CN)(Ph 3P) 2]· CH 3CN has been prepared by the reaction of [ReN(NCS) 2(Ph 3P) 2] with CH 3CN. Both complexes are air-stable. They have been characterized spectroscopically. The crystal and molecular structure of [ReN(NCS) 2(CH 3CN)(Ph 3P) 2]·CH 3CN has been determined by single-crystal X-ray diffraction. [ReN(NCS) 2(CH 3CN)(Ph 3P) 2]·CH 3CN crystallizes in the monoclinic space group P2 1/ n ( a=9.242(3), b=18.506(3), c=21.773(6) Å, β=93.84(2)° with Z=4. The final R value is 0.042. The compound consists of discrete [ReN(NCS) 2(CH 3CN)(Ph 3P) 2] molecules with an additional CH 3CN solvent molecule per complex in the crystal lattice. The coordination sphere of the rhenium atom is a distorted octahedron, with a ReN bond length of 1.66(1) Å. The strong trans influence of the nitrido group is evident in the exceptionally long ReN bond distance (2.42(1) Å) to the CH 3CN ligand.