Synthesis and structure of complexes with nitrido bridges between rhenium and zinc

The reaction of [ReNCl2(PMePh)(3)] with ZnX2 (X = Cl, Br) in CH2Cl2 yields the tetranuclear complexes [(Me(2)PkP)(3)X2Re equivalent to N-ZnX2](2). In case of the reaction with ZnBr2 an exchange of the halogen atoms coordinate d to the Re atom occurs. [(Me2PhP)(3)Cl2Re equivalent to N-ZnCl2](2) (1) cr ystallizes with one centrosymmetric tetranuclear complex in the triclinic u nit cell. [(Me2PhP)(3)Br2Re equivalent to N-ZnBr2](2) (2) forms triclinic c rystals with the composition 2.2 CH2Cl2. The centrosymmetric tetranuclear c omplexes exhibit analogous structures. Two complexes [ReNX2(PMe2Ph)(3)] coo rdinate with the terminal nitrido ligands the Zn atoms of a central unit XZ n(mu-X)(2)ZnX. The resulting linear nitrido bridges Re equivalent to N-Zn ( Re-N-Zn = 178.4 degrees (1) und 178.0 degrees (2)) are asymmetric with dist ances Re-N = 170 pm and Zn-N = 199 pm for 1, and Re-N = 167 pm as well as Z n-N = 201 pm for 2. The reaction of [ReNCl2(PMe2Ph)(3)] with ZnI2 in CH2Cl2 presumably first affords [(Me2PhP)(3)ClIRe equivalent to N-ZnI2](2), which , however, in the course of crystallization decomposes to yield [(Me2PhP)(3 )ClIRe equivalent to N-ZnI2(OPMe2Ph)] (3). Of the two Cl atoms originally c oordinated at the Re atom the one in cis position to the nitrido ligand is substituted by iodine. 3 forms monoclinic crystals with the space group P2( 1)/n. The distances in the linear nitrido bridge (Re-N-Zn = 171.5 degrees) are Re-N = 167.9 pm and Zn-N = 204.9 pm. By the reaction of [ReNCl2(PMe2Ph) (3)] with ZnX2 (X = Cl, I) in THF the di nuclear complexes [(Me2PhP)(3)Cl2R e equivalent to N-ZnCl2(THF)] (4) and [(Me2PhP)(3)ClIRe equivalent to N-ZnI 2(THF)] (5) are obtained. They crystallize isotypically as 4 THF or 5 THF i n the triclinic space group P1. Their nitrido bridges have the following pa rameters: Re-N-Zn = 175.2 degrees, Re-N = 167.7 pm, and Zn-N=202.1pm for 4, resp. Re-N-Zn=174.7 degrees, Re-N=168.3 pm, and Zn-N = 201.2 pm for 5.