[Fc(2)B(2)(Br)(mu-NPEt3)(2)]Br-+(-) - a ferrocenyl-substituted phosphoraneiminato complex of boron

[Fc(2)B(2)(Br)(mu -NPEt3)(2)]Br-+(-) has been prepared from ferrocenylboron dibromide, [Fe(eta (5)-C5H5)(eta (5)-C5H4BBr2)], and the silylated phospho raneimine Me3SiNPEt3 in dichloromethane solution to give orange-red single crystals which were characterized by IR, NMR and Fe-57 Mossbauer spectra: a s well as by a crystal structure determination. [Fc(2)B(2)(Br)(mu -NPEt3)(2 )]Br-+(-). 3 (CHCl2)-Cl-2 (1 . 3 CH2Cl2): Space group P2(1)/n, Z=4, lattice dimensions at -50 degreesC: a=1370.6(3), b=2320.9(5), c = 1454.4(2), beta = 95.38(1)degrees, R-1 = 0.061. In the cation of 1 the ferrocenyl-substitut ed boron atoms are connected by the nitrogen atoms of the [NPEt3](-) groups to form a planar B2N2 four-membered ring. One of the boron atoms having pl a nar, the other tetrahedral coordination.