Synthesis and Characterization of Novel HomolepticN,N-Dialkylcarbamato Complexes of Antimony: Precursors for the Deposition of Antimony Oxides

Abstract

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).

Recent Advances in the Chemistry of Metal Carbamates

“…Indeed, [Ti(O 2 CNMe 2 ) 4 ], the first carbamato complex to be reported, was obtained by exhaustive carbonation of the N , N -dimethylamido complex of titanium(IV), Ti(NMe 2 ) 4 [ 122 ]. Since then, the M(NR 2 ) n /CO 2 route has been successfully employed in the preparation of homoleptic complexes of the main group metals [ 42 , 123 ], early transition elements [ 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 ], uranium(IV) and thorium(IV) [ 132 ]. In 2010, Kennedy et al applied this methodology to obtain Li + , Na + and K + 2,2,6,6-tetramethylpiperidine (TMP) carbamates [ 133 ].…”

Intramolecularly coordinated organoantimony(III) carboxylates

“…The phthalic acid was used as a bridging ligand between two antimony centres as well [11]. Compounds of the type Sb(OOCNR 2 ) 3 have been recently investigated as precursors for deposition of antimony oxides [12].…”

Deposition of Antimony and Antimony Oxides by MOCVD

“…Films were produced by APCVD using the precursors listed above in an Aftek hot-wall reactor in the temperature range 150±650 C, and a cold-wall reactor [14] in the range 300±500 C. LPCVD was carried out in a hot-wall reactor at 380 C [13].…”

“…Details of the relevant deposition process and the nature of some of those films have been reported elsewhere [9,12,13]. Additional films have now been produced over a wider range of temperatures and process conditions.…”

“…However, in these preliminary experiments using a rudimentary reactor, temperature control was not very precise. Subsequent work has made use of tris(N,N-dimethylcarbamato)antimony(III) (Sb(O 2 CNMe 2 ) 3 ), [13] and antimony(III) neopentoxide (Sb(OCH 2 CMe 3 ) 3 ) for low-pressure (LP) MOCVD.…”