Macrocycles containing 1,1′-ferrocenyldiselenolato ligands on group 4 metallocenes

Abstract

were prepared and characterized by 77 Se NMR spectroscopy and the crystal structures of 1-3 and 5 were determined by single-crystal X-ray diffraction. The crystal structure of 4 is known and the complex is isomorphous with 5. 1-5 form mutually similar macrocyclic tetranuclear complexes in which the alternating Fe(C 5 H 4 Se) 2 and M(C 5 H 4 R) 2 centers are linked by selenium bridges. The thermogravimetric analysis (TGA) of 1-3 under a helium atmosphere indicated that the complexes undergo a two-step decomposition upon heating. The final products were identified using powder X-ray diffraction as Fe x MSe 2 , indicating their potential as single-source precursors for functional materials.

Accessing new 2D semiconductors with optical band gap: synthesis of iron-intercalated titanium diselenide thin films via LPCVD

“…The precursors were synthesized according to literature. 22 N , N , N ′, N ′-Tetramethylethylenediamine (Aldrich) was distilled over sodium and stored over sieves 3 Å (20% m/v) for 24 h and ferrocene (Merck, 99%) was freeze dried for 12 h prior to use. Selenium (shot, Aldrich), nBuLi (2.5 M in Hexane, Aldrich), t BuLi (1.7 M in Hexane, Aldrich) and bis(cyclopentadienyl)titanium( iv )dichloride (Aldrich) were used as purchased.…”

“…After isolation, the polycrystalline powder precursor was stored in a glovebox under an Argon atmosphere. Synthesis and purification of the precursor was confirmed by NMR: 22 1 H NMR (600 MHz) δ /ppm (C 6 D 6 ): 5.67 (s, 10H); 4.35 (m, 8H). 13 C{ 1 H} NMR (600 MHz) δ /ppm (C 6 D 6 ): 110.99 (m, Fc); 111.26 (m, Cp).…”

“…16,18,21 The decomposition of metal chalcogenolato complexes to metal chalcogenides takes place at signicantly lower temperatures, and they provide high purity materials required for electronic applications. Recent research has highlighted the importance of careful precursor design, in order to facilitate cleaner decomposition, 22 lowering contamination and improving performance of the resultant functional material. Chemical vapour deposition (CVD) has drawn attention as a method to synthesis thin lms of functional materials, 23 including metal selenides.…”

“…reported 22 for potential utilization as single source precursors. In particular, the use of the titanium species 1 in the LPCVD fabrication of iron intercalated titanium diselenide Fe x TiSe 2 could remove any pre-reaction issues or formation of unwanted side products and facilitates a facile, one step route to functional semiconductor materials with tuneable band gap.…”

“… 24,25 The use of single source precursors in CVD has a number of advantages, not least the simplification of the decomposition mechanism since all required elements are delivered to the desired substrate at the same time. Earlier this year compounds of the type: [Fe(η 5 -C 5 H 4 Se) 2 M(η 5 -C 5 H 5 ) 2 ] 2 [M = Ti (1), Zr (2), Hf (3)] have been reported 22 for potential utilization as single source precursors. In particular, the use of the titanium species 1 in the LPCVD fabrication of iron intercalated titanium diselenide Fe x TiSe 2 could remove any pre-reaction issues or formation of unwanted side products and facilitates a facile, one step route to functional semiconductor materials with tuneable band gap.…”