Synthesis, solution dynamics and chemical vapour deposition of heteroleptic zinc complexes ethyl and amide zinc thioureides.

Ethyl and amide zinc thioureides [LZnEt] (), [L*ZnEt] () and [LZn(N(SiMe))] () have been synthesised from the equimolar reaction of thiourea ligands (HL = PrN(H)CSNMe and HL* = PhN(H)CSNMe) with diethyl zinc and zinc bis[bis(trimethylsilyl)amide] respectively. New routes towards heteroleptic complexes have been investigated through reactions of , and with β-ketoiminates (HL = [(Me)CN(H){Pr}-CHC(Me)[double bond, length as m-dash]O]), bulky aryl substituted β-diiminates (HL = [(Me)CN(H){Dipp}-CHC(Me)[double bond, length as m-dash]N{Dipp}] (Dipp = diisopropylphenyl) and HL* = [(Me)CN(H){Dep}-CHC(Me)[double bond, length as m-dash]N{Dep}] (Dep = diethylphenyl)) and donor-functionalised alcohols (HL = EtN(CH)OH and HL* = MeN(CH)OH) and have led to the formation of the heteroleptic complexes [L*ZnL*] (), [LZnL] (), [LZnL*] (), [L*ZnL] () and [L*ZnL*] (). All complexes have been characterised by H and C NMR, elemental analysis, and the X-ray structures of HL*, , , and have been determined single crystal X-ray diffraction. Variable temperature H, COSY and NOESY NMR experiments investigating the dynamic behaviour of , and have shown these molecules to be fluxional. On the basis of solution state fluxionality and thermogravimetric analysis (TGA), alkoxyzinc thioureides and were investigated as single-source precursors for the deposition of the ternary material zinc oxysulfide, Zn(O,S), a buffer layer used in thin film photovoltaic devices. The aerosol-assisted chemical vapour deposition (AACVD) reaction of at 400 °C led to the deposition of the heterodichalcogenide material Zn(O,S), which was confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray analysis (EDX), with optical properties investigated using UV/vis spectroscopy, and surface morphology and film thickness examined using scanning electron microscopy (SEM).