Homoleptic copper(I) arylthiolates as a new class of p-type charge carriers: structures and charge mobility studies

Polymeric homoleptic copper(I) arylthiolates [Cu(p-SC(6)H(4)-X)](infinity) (X=CH(3) (1), H (2), CH(3)O (3), tBu (4), CF(3) (5), NO(2) (6), and COOH (7)) have been prepared as insoluble crystalline solids in good yields (75-95 %). Structure determinations by powder X-ray diffraction analysis have revealed that 1-3 and 6 form polymers of infinite chain length, with the copper atoms bridged by arylthiolate ligands. Weak intra-chain pi***pi stacking interactions are present in 1-3, as evidenced by the distances (3.210 A in 1, 3.016 A in 2, 3.401 A in 3) between the mean planes of neighboring phenyl rings. In the structure of 6, the intra-chain pi***pi interactions (d=3.711 A) are insignificant and the chain polymers are associated through weak, non-covalent C-H...O hydrogen-bonding interactions (d=2.586 A). Samples of 1-7 in their polycrystalline forms proved to be thermally stable at 200-300 degrees C; their respective decomposition temperatures are around 100 degrees C higher than that of the aliphatic analogue [Cu(SCH(3))](infinity). Data from in situ variable-temperature X-ray diffractometry measurements indicated that the structures of both 1 and 7 are thermally more robust than that of [Cu(SCH(3))](infinity). TEM analysis revealed that the solid samples of 1-5 and [Cu(SCH(3))](infinity) contained homogeneously dispersed crystalline nanorods with widths of 20-250 nm, whereas smaller plate-like nanocrystals were found for 6 and 7. SAED data showed that the chain polymers of 1-3 and [Cu(SCH(3))](infinity) similarly extend along the long axes of their nanorods. The nanorods of 1-5 and [Cu(SCH(3))](infinity) have been found to exhibit p-type field-effect transistor behavior, with charge mobility (micro) values of 10(-2)-10(-5) cm(2) V(-1) s(-1). Polycrystalline solid samples of 6 and 7 each showed a low charge mobility (<10(-6) cm(2) V(-1) s(-1)). The charge mobility values of field-effect transistors made from crystalline nanorods of 1-3 and [Cu(SCH(3))](infinity) could be correlated with their unique chain-like copper-sulfur networks, with the para-substituent of the arylthiolate ligand influencing the charge-transport properties.     

Hopeahainol A: an acetylcholinesterase inhibitor from Hopea hainanensis

A phytochemical study of Hopea hainanensis has led to the isolation of three new polyphenols and one known compound. The most important of these compounds are hopeahainols A (2) and B (3), which contain an unprecedented carbon skeleton. The structures were elucidated by analysis of the spectroscopic data including single-crystal X-ray spectroscopy and computational methods. Hopeahainol A was an acetylcholinesterase inhibitor with an IC50 value of 4.33 microM, which is comparable to that of huperzine A, a presently prescribed drug for the treatment of Alzheimer, while other similar structures were inactive. This observation was complemented by a 3D interaction model of the inhibitor with active sites.     

Systematic reactions of [Pt(PF3)4

Tetrahedral [Pt(PF(3))(4)] reacts with H(+) to form trigonal bipyramidal [Pt(PF(3))(4)H](+). This in turn looses PF(3) to form square-planar [Pt(PF(3))(3)H](+). The complex [Pt(PF(3))(4)] can be oxidized with AsF(5) to form the square-planar complex, [Pt(PF(3))(4)](2+), which can be more conveniently obtained from PtF(4) and PF(3) in HF/SbF(5) solution. [Pt(PF(3))(4)](2+) reacts with F(-) in HF under cluster formation to [Pt(4)(PF(3))(8)H](+).     

A Precoordination Complex of 1,2,3‐Trimethyl‐1,3,5‐triazacyclohexane with tert‐Butyllithium as Key Intermediate in Its Methylene Group Deprotonation

α‐Lithiated tertiary methylamines are important building blocks in all fields of chemistry, such as for the synthesis of new ligand or catalyst systems. However, the access to these compounds is still limited and the reaction mechanism, in general, not fully understood. We present herein X‐ray diffraction analyses of organolithium compounds with 1,2,3‐trimethyl‐1,3,5‐triazacyclohexane ( 1 ), such as a precoordination adduct of tert‐butyllithium, [(tBuLi)₃?C₆H₁₅N₃], which represents a potential intermediate of the lithiation of the methylene group of this ligand. By means of molecular structures and computational studies, the regioselectivity of this deprotonation reaction can be understood. Furthermore, the tBuLi adduct gives a hint to an alternative deaggregation process of organolithium compounds.