Synthesis and characterization of novel homoleptic N,N-dialkylcarbamato complexes of antimony:: Precursors for the deposition of antimony oxides

A series of tris(NN-dialkylcarbamato)antimony(III) complexes, Sb(O2CNR2)(3) (R = Me, Et, Pr'), have been synthesized and are the first members of this class of compound to have been crystallographically characterized. Sb(O2CNMe2)(3) (1) exists as a weakly bound dimer, whereas its diethyl and diisopropyl analogues (2, 3) are monomeric. In addition, tetrakis(N,N-diethylcarbamato)tin(IV) (4) has been prepared for comparison and shown by single-crystal X-ray analysis to exhibit the relatively rare SnO8 coordination. Crystallographic data: for 1, a = 8.7520(5) Angstrom, b = 14.2970(8) Angstrom, c = 11.8150(7) Angstrom, beta = 108.029(2)degrees, monoclinic, P2(1)/c, Z = 4; for 2, a = b = 14.4690(2) Angstrom, c = 16.6740(2) Angstrom, trigonal, R (3) over bar, Z = 6; for 3, a = 11.9881(2) Angstrom, b = 11.6521(3) Angstrom, c = 19.8780(6) Angstrom, beta = 90.401(1)degrees, monoclinic, P2(1)/n, Z = 4; for 4, a = 13.9654(2) Angstrom, b = 12.0817(2) Angstrom, c = 16.6752(2) Angstrom, beta = 108.1960(7)degrees, monoclinic, C2/c, Z = 4. Sb(O2CNMe2)(3) has been used as a single-source precursor in the low-pressure chemical vapor deposition of the senarmonite form of Sb2O3.