5-(perfluoroalkyl)tetrazoles: ή5Ligands in Solution and μ-2,3-ή2Ligands in Solid Complexes

Abstract

Sodium azide was reacted with (difluoroamino)difluoroacetonitrile, NF2CF2CN (1), to give sodium 5-((difluoroamino)difluoro-methyI)tetrazolate (2) in a reaction analogous to that with CF3CN where the previously known sodium 5-(trifluoromethyl)tet-razolate (3) was formed. Reactions of 2 and 3 with pentacarbonylmanganese bromide give the compounds RfCNNNNMn(CO)3(Rf= NF2CF2, CF3). In solution, the local symmetry of the carbonyl groups is very similar to that of (π-C5H5)Mn(CO)3, which is an ή5-π complex. However, upon evaporation of the solvent, a reversible reorganization of the ligands gives rise to the compounds [(RfCNNNN)3Mn2(CO)6]Mn(CO)3(Rf= NF2CF2(6), CF3(7)). The latter anion has been characterized by X-ray structural analysis of the compound [(CF3CNNNN)3Mn2(CO)6]-;[Na(diglyme)2]· (8). In the solid, the tetrazole ligands are of the ή2type with N-2 and N-3 of each tetrazole bridging between the two manganese atoms. The N-2-N-3 distance (1.34 Å) is much longer than that observed previously in copper and silver salts (1.12 Å). © 1989, American Chemical Society. All rights reserved.