Electrochemical synthesis of copper and silver pyridine-2-selenolato complexes: crystal structure of (6-trimethylsilylpyridine-2-selenolato)silver(I), [Ag6(6-Me3SipySe)6]

Facile one pot synthesis of highly photoresponsive coinage metal selenides (Cu1.8Se and Ag2Se) achieved through novel Cu and Ag pyridylselenolates as molecular precursors

Copper selenide (Cu_1.8Se) and silver selenide (Ag₂Se) have garnered unprecedented attention as efficient absorber materials for cost-effective and sustainable solar cells. Phase pure preparation of these exotic materials in a nano-regime is highly desirable. This account outlines a simple and easily scalable pathway to Cu_1.8Se and Ag₂Se nanocrystals using novel complexes [Cu{2-SeC₅H₂(Me-4,6)₂N}]₄ (1), [Ag{2-SeC₅H₂(Me-4,6)₂N}]₆ (2) and [Ag{2-SeC₅H₃(Me-5)N}]₆·2C₆H₅CH₃ (3·2C₆H₅CH₃) as single source molecular precursors (SSPs). Structural studies revealed that the Cu and Ag complexes crystallize into tetrameric and hexameric forms, respectively. This observed structural diversity in the complexes has been rationalized via DFT calculations and attributed to metal-metal bond endorsed energetics. The thermolysis at relatively lower temperature in oleylamine of complex 1 afforded cubic berzelianite Cu_1.8Se and complexes 2 and 3 produced orthorhombic naumannite Ag₂Se nanocrystals. The low temperature synthesis of these nanocrystals seems to be driven by the observed preformed Cu₄Se₄ and Ag₆Se₆ core in the complexes which have close resemblance with the bulk structure of the final materials (Cu_1.8Se and Ag₂Se). The crystal structure, phase purity, morphology, elemental composition and band gap of these nanocrystals were determined from pXRD, electron microscopy (SEM and TEM), EDS and DRS-UV, respectively. The band gap of these nanocrystals lies in the range suitable for solar cell applications. Finally, these nanocrystal-based prototype photo-electrochemical cells exhibit high photoresponsivity and stability under alternating light and dark conditions.

Metal Nanoclusters Stabilized by Selenol Ligands

The past decades have witnessed great advances in controllable synthesis, structure determination, and property investigation of metal nanoclusters. Selenolated nanoclusters, a special branch in the nanocluster family, have attracted great interest in these years. The electronegativity and atomic radius of selenium is different from sulfur, and thus the selenolated nanoclusters are anticipated to display different electronic/geometric structures and distinct chemical/physical properties relative to their thiolated analogues. This review covers the syntheses, structures, and properties of selenolated nanoclusters (including Au, Ag, Cu, and alloy nanoclusters). Ligand effects (between SeR and SR) on nanocluster properties, including optical absorption, stability, and electrochemical properties, are disclosed as well. At the end of the review, a scope for improvements and future perspectives of selenolated nanoclusters is highlighted. The review hopefully opens up new horizons for cluster scientists to synthesize more selenolated nanoclusters with novel structures and properties. This review is based on publications available up to May 2019.

Applications of metal selenium/tellurium compounds in materials science

Metal chalcogenides are technologically important materials. Physical, chemical, electrical and mechanical properties of these materials can be fine-tuned by manipulating their shape, size and composition. Although several methods are employed for their synthesis, single-source molecular precursor route has emerged as a versatile strategy for their synthesis and in controlling shape, size and composition of the material under moderate conditions. This chapter gives a brief coverage on the design and development of single-source molecular precursors which have been employed for the preparation of metal selenide/telluride nanocrystals and for deposition of thin films. The discussion includes synthesis of transition-, main group and f-block metal chalcogenolate and/or chalcogenide clusters as precursors and their conversion into metal chalcogenides in the form of thin films and nanostructures. Precursors for ternary metal chalcogenides are also included.

Pyridyl and pyrimidyl chalcogenolates of coinage metals and their utility as molecular precursors for the preparation of metal chalcogenides

Synthesis of and metallophilic interactions in N-heterocyclic chalcogenolates of coinage metals have been described and their utility as molecular precursors for binary and ternary chalcogenide materials has been demonstrated.

Emerging trends in organotellurolate chemistry derived from platinoids

This perspective begins with the discussion of various basic synthetic approaches applied for the synthesis of several organotellurium ligands, their chemistry derived from platinum group metals, and the reactivity difference among them.

Hemilabile silver(i) complexes containing pyridyl chalcogenolate (S, Se) ligands and their utility as molecular precursors for silver chalcogenides

A series of silver triphenylphosphine complexes containing pyridyl chacogenolate (S, Se) ligands has been synthesized by employing [AgCl(PPh₃)₃] and [Ag₂(μ-Cl)₂(PPh₃)₄].

Synthesis, structures and DFT calculations of 2-(4,6-dimethyl pyrimidyl)selenolate complexes of Cu(i), Ag(i) and Au(i) and their conversion into metal selenide nanocrystals

Dimethyl pyrimidylselenolates of Cu(i), Ag(i) and Au(i) were synthesized and utilized as precursors for preparation of the respective metal selenide nanocrystals.