Synthesis and materials chemistry of bismuth tris-(di-i-propylcarbamate): deposition of photoactive Bi2O3 thin films.

The bismuth carbamate Bi(O2CNPr(i)2)3, a tetramer in the solid-state, has been synthesized and used to deposit mixtures of bismuth oxides by aerosol-assisted chemical vapor deposition (AACVD). The nature of the deposited oxide is a function of both temperature and run-time. Initially, δ-Bi2O3 is deposited, over which grows a thick layer of ß-Bi2O3 nanowires, the latter having an increasing degree of preferred orientation at higher deposition temperatures. The photocatalytic activity of a thin film of δ-Bi2O3 for the degradation of methylene blue dye was found to be similar to that of a commercial TiO2 film on glass, while the film overcoated with ß-Bi2O3 nanowires was less active. Exposure of Bi(O2CNPr(i)2)3 to controlled amounts of moist air affords the novel oxo-cluster Bi8(O)6(O2CNPr(i)2)12, whose structure has also been determined.

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

A series of tris(N,N-dialkylcarbamato)antimony(III) complexes, Sb(O(2)CNR(2))(3) (R = Me, Et, Pr(i)()), have been synthesized and are the first members of this class of compound to have been crystallographically characterized. Sb(O(2)CNMe(2))(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 SnO(8) coordination. Crystallographic data: for 1, a = 8.7520(5) A, b = 14.2970(8) A, c = 11.8150(7) A, beta = 108.029(2) degrees, monoclinic, P2(1)/c, Z = 4; for 2, a = b = 14.4690(2) A, c = 16.6740(2) A, trigonal, Rthremacr;, Z = 6; for 3, a = 11.9881(2) A, b = 11.6521(3) A, c = 19.8780(6) A, beta = 90.401(1) degrees, monoclinic, P2(1)/n, Z = 4; for 4, a = 13.9654(2) A, b = 12.0817(2) A, c = 16.6752(2) A, beta = 108.1960(7) degrees, monoclinic, C2/c, Z = 4. Sb(O(2)CNMe(2))(3) has been used as a single-source precursor in the low-pressure chemical vapor deposition of the senarmonite form of Sb(2)O(3).

Structures of Sb(OC(6)H(3)Me(2)-2,6)(3) and Sb(OEt)(5) x NH(3): the first authenticated monomeric Sb(OR)(n) (n = 3, 5).

The first monomeric antimony alkoxides, Sb(OC(6)H(3)Me(2))(3) (1) and Sb(OEt)(5) x NH(3) (2), have been crystallographically characterized. The former adopts a trigonal pyramidal geometry, while the latter is octahedral about antimony; hydrogen bonding between NH(3) and SbOEt groups in Sb(OEt)(5) small middle dotNH(3) creates a one-dimensional lattice arrangement. Reaction of pyridine with SbCl(5) in EtOH/hexane yields the salt [Hpy(+)](9)[Sb(2)Cl(11)(5)(-)][Cl(-)](4) (3), which has also been crystallographically characterized. Crystallographic data: 1, C(24)H(27)O(3)Sb, a = 10.9080(2), b = 11.9660(2), c = 17.7260(4) A, alpha = 109.740(1) degrees, monoclinic P2(1)/c (unique axis a), Z = 4; 2, C(10)H(28)NO(5)Sb, a = 7.7220(1), b = 19.0700(2), c = 21.6800(3) A, beta = 93.4960(7) degrees, monoclinic P2(1)/c, Z = 8; 3, C(45)H(54)Cl(15)N(9)Sb(2), a = 13.4300(2), b = 14.4180(2), c = 17.4180(3) A, alpha = 82.7650(7), beta = 77.5570(7), gamma = 70.7670(7) degrees, triclinic P1, Z = 2.