New synthetic access to two-dimensional transition metal dichalcogenides (TMDCs) is highly desired to exploit their extraordinary semiconducting and optoelectronic properties for practical applications. We introduce here an entirely novel class of molecular precursors, [MIV(XEtN­(Me)­EtX)2] (MIV = MoIV, WIV, X = S, Se), enabling chemical vapor deposition of TMDC thin films. Molybdenum and tungsten complexes of dianionic tridentate pincer-type ligands (HXEt)2NR (R = methyl, tert-butyl, phenyl) produced air-stable monomeric dichalcogenide complexes, [W­(SEtN­(Me)­EtS)2] and [Mo­(SEtN­(Me)­EtS)2], displaying W and Mo centers in an octahedral environment of 4 S and 2 N donor atoms. Owing to their remarkable volatility and clean thermal decomposition, both Mo and W complexes, when used in the chemical vapor deposition (CVD) process, produced crystalline MoS2 and WS2 thin films. X-ray diffraction analysis and atomic-scale imaging confirmed the phase purity and 2D structural characteristics of MoS2 and WS2 films. The new set of ligands presented in this work open ups convenient access to a scalable and precursor-based synthesis of 2D transition metal dichalcogenides.

A new gold(II) species [(CF(3))(4)Au(2)(C(5)H(5)N)(2)] with a very short unsupported Au-Au bond (250.62(9) pm) was generated by photo irradiation of a silver aurate, [Ag(Py)(2)][Au(CF(3))(2)], unambiguously characterized by (19)F and (109)Ag NMR studies.

Phase controled chemical synthesis of 2D SnEx (E = S, Se; x = 1, 2) using new, well-characterized molecular precursors is presented.

Two new cobalt precursors, Co(II)(PyCHCOCF3)2(DMAP)2 (1) and Co(III)(PyCHCOCF3)3 (2), based on Co(II) and Co(III) centers were synthesized using a redox active ligand system. The different chemical configurations of 1 and 2 and differential valence states of cobalt were confirmed by crystal structure determination and comprehensive analytical studies. Whereas 1 could not be studied by NMR due to the paramagnetic nature of the central atom, 2 was unambiguously characterized by multinuclear 1D and 2D NMR experiments in solution. Both compounds are efficient precursors for catalyst-free growth of Co3O4 nanowires on Si and Al2O3 substrates by a chemical vapor deposition process. The different valence states of cobalt species influenced their chemical decomposition pathways in the gas phase; for instance, 1 was partially oxidized (Co(2+) → Co(3+)), and 2 underwent reduction (Co(3+) → Co(2+)) to form pure cobaltite in both cases that verified the metal-ligand redox interplay. Co3O4 nanowires with nanometric diameters (50-100 nm) were obtained irrespective of the chosen cobalt precursor. Investigations on the humidity sensing behavior of CVD deposits demonstrated their potential as promising sensor materials.

n = 1, 2) were obtained by the scission of the Cd−I bond in the iodo heterobimetallic isopropoxide [ICd{Zr 2 (OPr i ) 9 }] (1), whereby the underlying synthetic strategies involve metathesis reactions with silver salts or Lewis acid−base interactions between the Brønsted acid [Zr-(OPr i ) 4 (HOPr i )] 2 and bis(fluoroorgano)cadmium (Cd(R f ) 2 ) compounds. The new compounds were characterized by multinuclear NMR spectroscopy, elemental analysis, and mass spectrometry. The results of X-ray diffraction analysis of 11), and [(μ-O 2 SOCF 3 )Cd{Zr 2 (OPr i ) 9 }] 2 (12) revealed the molecular framework to be formally constituted by tetradentate coordination of a nonaisopropoxo dizirconate unit, {Zr 2 (OPr i ) 9 } − , to a CdX + unit. In solution and in the solid state, 1−7 exist as monomers, whereas compounds 8−12 form dimers.

Multiple silver(I)-aurates(I) have been prepared by salt metathesis reactions that act as efficient single-source precursors to colloidal gold silver alloys with the highest possible atom economy in the chemical synthesis of nanostructures. The CF3 group present on the Au cation acts as an in situ reducing agent and can be converted into CO ligands by simple hydrolysis. This ligand-mediated activation and subsequent decomposition of metal-organic precursors impose a molecular control over the nucleation process, producing homogeneously alloyed (Ag-Au) nanoparticles with an atomic Au:Ag ratio of 1:1. The concept also works for the Au-Cu system and acts as a pointer to replace Au (Ag) with less expensive (Cu) metals.

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New chemical routes to synthesize layered 2D transition metal dichalcogenides (TMDCs) are highly desired. We report here a new class of molecular precursors of general formula [MIV(SC2H4N(Me)C2H4S)2] (MIV=Ti, Zr, Hf) that offers a reliable synthetic access to 2D TMDC materials as demonstrated in the representative case of TiS2 synthesis. The complexation of the TM centers by the chelating tridentate ligand (HSC2H4)2NMe produced stable monomeric complexes, [Ti(SC2H4N(Me)C2H4S)2], [Zr(SC2H4N(Me)C2H4S)2] and [Hf(SC2H4N(Me)C2H4S)2], displaying a distorted octahedral environment around metal centers formed by four S and two N donor atoms of the ligand moiety. The characterization of molecular precursors by NMR, single‐crystal diffraction analysis, IR spectroscopy and elemental analysis confirmed the presence of metal‐sulfur bonds that are crucial in facilitating the formation of MS2 phases. Thermal decomposition behaviour of the three molecular compounds was investigated by TG‐DCS measurements that confirmed their decomposition into solid phases. Interestingly, the preorganized M−S bonds in the precursor molecules also influenced the formation of titanium disulfide thin films by chemical vapor phase deposition. The solid thin films of TiS2 were characterized by X‐ray spectroscopy analysis and atomic scale imaging. The complexes presented in this work represent a promising chemistry driven approach towards reproducible and scalable synthesis of van der Waals 2D heterostructures.