The aminolysis reaction between MN’’2 (N’’ = N(SiMe3)2; M = Fe, Co, Ni) and the neutral pro-ligand 6,6'-(1,4-phenylenebis(propane-2,2-diyl))bis(2,4-di-tert-butylphenol) (LH2) affords the low coordinate, isomorphous, monomeric bis-aryloxide complexes (2-M) (M =...

A base-catalyzed protocol is reported for the construction of 1,3-thiazolidine-2-thione scaffolds bearing quaternary carbon centers from carbon disulfide and α-tertiary propargylamines. The reaction proceeds using low catalyst loading, under ambient temperatures, and in the absence of solvent. Various α-tertiary propargylamines have been employed, affording a series of previously unreported thiazolidine-2-thione compounds and avoiding purification via column chromatography in certain cases. We also describe a one-pot strategy for the synthesis of the same products through a KA2 coupling-CS2 incorporation approach. The reaction mechanism and substituent-dependent catalytic behavior were studied through a combination of detailed experimental and computational studies.

The synthesis and characterisation of two square planar {PdNO}10 pincer complexes of the form [Pd(pincer)(NO)]+ (pincer = 2,6-(tBu2PCH2)2C5H3N, 1; 2,6-(tBu2PO)2C5H3N, 2) are reported. These complexes are readily isolated by phosphine substitution of T-shaped [Pd(PtBu3)2(NO)]+ 3 in THF and the bent nitrosyl coordination mode observed in 3 is retained, as evidenced by X-ray diffraction (∠PdNO ∼ 120°), IR spectroscopy and analysis of isotopically enriched samples by 15N NMR spectroscopy. Effective oxidation states of Pd0/NO+ are calculated for 1–3 and nitrosyl coordination is principally attributed to metal-centred σ-bonding, with supplementary π-backbonding. Computational analysis, however, indicates that the Pd−NO bonds in 1 and 2 have greater PdI/NO• character and σ-bonding is more prominent than in 3. These differences in bonding are manifested experimentally in more red-shifted nitrosyl stretching frequencies and the propensity of 1 and 2 to react with dichloromethane to afford palladium(II) chloride derivatives.

Thuwalamides A–E (1, 3, 5, 6 and 8), previously undescribed polychlorinated amides, along with ten previously reported related compounds (2, 4, 7 and 9–15), were isolated from the organic extract of the marine sponge Lamellodysidea herbacea (Keller), collected off the village of Thuwal in the Red Sea at Saudi Arabia. The structures of the isolated compounds have been determined through extensive analysis of their NMR and MS data, while their absolute stereochemistry was unequivocally established via single crystal X-ray diffraction. Additionally, the absolute stereochemistry of the previously reported compounds 2 and 4, whose configuration was not determined, has also been established using single-crystal X-ray crystallographic analysis. The antibacterial activity of compounds 1–15 was evaluated against Escherichia coli and Staphylococcus aureus. Among them, compound 14 displayed activity against S. aureus comparable to vancomycin that was used as a positive control with a MIC value of 4 μg/mL.

We report on the preparation, crystal structure and spectral properties of the novel trimethylsulfonium tin tribromide, [(CH3)3S]SnBr3. The compound was synthesized by the solid-state reaction of (CH3)3SBr and SnBr2 in evacuated pyrex tubes at 150 °C. Single-crystal X-ray diffraction (SCXRD) studies at −173.15 °C show that it forms a 0D network of isolated pyramids of [SnBr3]− and (CH3)3S+ units in an orthorhombic structure (space group P212121, No. 19, a = 9.4508(8) Å, b = 14.1691(12) Å, c = 15.4409(14) Å)). Powder X-ray diffraction (PXRD) and Le bail profile fit analysis reveals that [(CH3)3S]SnBr3 adopts at room temperature a different crystal structure with space group (Pmmm, No. 47). Moreover, the oxidation of the compound occurs gradually in ambient air, towards the formation of [(CH3)3S)]2SnBr6 (space group Pa-3, No. 205). Multi-temperature Raman spectroscopy reveals that a fully reversible structural phase transition occurs for [(CH3)3S]SnBr3 between −36 and −56 °C, as evidenced by the changes in the vibrational modes of the [SnBr3]− ions. A direct band gap of 3.38 eV at RT is determined via UV–vis diffuse reflectance spectroscopy. Photoluminescence spectroscopy at −196.15 °C and 25 °C shows a weak luminescence signal with an emission maximum at ca. 460 nm for both temperatures.