Synthesis and properties of MoCl₄complexes with thio- and seleno-ethers and their use for chemical vapour deposition of MoSe₂and MoS₂films

Abstract

Treatment of trans-[MoCl(MeCN)] with L (L = MeS, MeSe, THT, ½MeSCHCHSMe) in CHCl solution, or reaction of MoCl with excess L' (L' = BuS, BuSe, ½MeSCHCHSMe, ½PrSCHCHSPr, ½MeSCHCHCHSMe, ½MeSeCHCHCHSeMe) in MeCN, produces the Mo(iv) complexes, [MoCl(L)] and [MoCl(L')], respectively, in good yield. The new complexes have been characterised by IR and UV-vis spectroscopy, elemental analysis and magnetic measurements, whilst crystal structure analyses of trans-[MoCl(MeS)], cis-[MoCl{RS(CH)SR}] (R = Me, Pr) and cis-[MoCl{MeS(CH)SMe}] confirmed their identities and distorted octahedral geometries. The potential of [MoCl(BuE)] (E = S, Se) as the first examples of molybdenum halide derived single source CVD precursors for the growth of MoE thin films was first probed by TGA, which showed multi-step decomposition processes, with the masses of the final residues consistent with MoSe (E = Se) and MoCl (E = S), respectively. Low pressure CVD experiments conducted at 750 °C (E = S) and 525 °C (E = Se) gave silvery and golden yellow films, respectively. Grazing incidence and in plane XRD data confirmed these to be 2H-MoE, whilst the texture of the MoSe was investigated using pole figure measurements. SEM and EDX data, optical and Raman data on the films are also reported.

Coinage Metal Complexes with Di‐tertiary‐butyl Sulfide as Precursors with Ultra‐Low Decomposition Temperature

“…[19][20][21][22][23] On the contrary, the exploit of non-silylated chalcogenoethers R 2 E (R = a non-silylated alkyl group; E = S, Se, Te) have been mainly restricted to the elaboration of thin films by chemical vapor deposition technique requiring usually high temperature. [24,25] Only recently, we have employed nonsilylated selenoether ligands, particularly the ones having facile decomposition mechanism, [26] for the first time in the solutionphase synthesis of metal selenide NPs for the photocatalytic applications. [27][28][29][30] Thus, the reactions of t Bu 2 Se with coinage metal reagents not only resulted in the formation of binary and ternary metal selenide NPs at room temperature (RT) but also allowed us to isolate and characterize highly reactive molecular intermediates during the reactions.…”

Ultra-mild synthesis of nanometric metal chalcogenides using organyl chalcogenide precursors

“…For instance, Reid et al have synthesized many metal halide complexes with the di-n-butyl chalcogenide ligand [MCl 4 ( n Bu 2 E) 2 ] (M = Ti, Sn, Mo; E = S or Se), the thermogravimetric analyses (TGA) of which showed their low thermal decomposition (typically below 250 1C). [58][59][60] The C-Se bond is slightly weaker than the C-S bond and, therefore, the n Bu 2 Se analogues are expectedly decomposed at slightly lower temperature than those with the n Bu 2 S ligand. These precursors were employed in MOCVD to deposit metal chalcogenide thin films.…”

Synthesis, characterization, X-ray and electronic structures of diethyl ether and 1,2-dimethoxyethane adducts of molybdenum(iv) chloride and tungsten(iv) chloride

“…Surprisingly, the diethyl ether and dme complexes lack characterization outside of elemental analyses despite there being extensive characterization of various MCl 4 L 2 complexes with O-, S-, and Se-donor ligands. [34][35][36][37][38][39] In the present report, we describe reliable syntheses, compare the X-ray structures of all four compounds, and provide magnetic data on the Mo and W dme adducts. We also discuss the electronic structures of these pseudo-octahedral d 2 complexes.…”