Heraclio López-Ruiz

Engineering organic semiconducting solids. Multicomponent access to crystalline 3-(4-aryl-1,2,3-triazolyl)coumarins

Crystalline 3-(4-aryl-1,2,3-triazol-1-yl)coumarins (ATCs) were prepared from commercial materials using a four-component methodology as a key step. In the present work, a feasible and environmentally friendly route to the title compounds was developed through the reaction between salicylaldehydes, ethyl bromoacetate, phenylacetylenes and sodium azide under mild conditions, with short reaction times and a simple workup. Crystalline solids are readily accessed from the featured products via solution processing and their arrays in the solid state were elucidated through SXRD; these molecules display a periodic overlap of π-systems, which facilitates carrier transport in organic electronic devices. Semiconductor band gaps for the obtained solids were derived through plane-wave DFT and compared with reference systems known to display superior performance in organic electronics. Thus ATCs represent attractive systems for research and implementation in molecular materials, a task which will be facilitated by the concise route herein described.

A practical access to acyl radicals from acyl hydrazides.

Various acyl radicals can be generated from the corresponding acyl triphenylmethyldiazo derivatives, produced by in situ oxidation of hydrazide precursors with phenylseleninic acid.

O-Ethyl S-{(S)-1-oxo-1-[(R)-2-oxo-4-phenyl-oxazolidin-3-yl]propan-2-yl} carbonodi-thio-ate.

In the title compound, C15H17NO4S2, synthesized by addition of O-ethylxanthic acid potassium salt to a diastereomeric mixture of (4R)-3-(2-chloropropanoyl)-4-phenyloxazolidin-2-one, the oxazolidinone ring has a twist conformation on the C—C bond. The phenyl ring is inclined to the mean plane of the oxazolidinone ring by 76.4 (3)°. In the chain the methine H atom is involved in a C—H⋯S and a C—H⋯O intramolecular interaction. In the crystal, molecules are linked by C—H⋯π interactions, forming chains along [001]. The S configuration at the C atom to which the xanthate group is attached was determined by comparison to the known R configuration of the C atom to which the phenyl group is attached.

Coordination diversity in tin compounds with bis(benzoxazole)phenol as a polydentate ligand: Synthesis and crystal structure studies

Abstract The reaction of 2,6-bis(benzoxazolyl)-4-tert-butylphenol (HL) with [nBuxSnCl4−x] (x = 0, 1) in 1:1 stoichiometry yielded the tin coordination complexes [(HL)SnnBuxCl4−x] [x = 0 (1); x = 1 (2)]. Deprotonation of HL was performed using reagents having groups with high basicity such as nBuLi or [Sn{N(SiMe3)2}2]. These basic reagents prompted the coordination of the ligand in its anionic form, yielding the complexes [(thf)2Li(L)SnCl4] (3) and [(L)Sn{N(SiMe3)2}] (4), respectively. The molecular structure of HL displayed an intramolecular hydrogen bond OH—N and a planar arrangement of the bis(benzoxazolyl)phenolic system. In the molecular structures of both complexes containing HL an intramolecular hydrogen bond of NH—O type was also present. The coordination of the ligand in either neutral or anionic form is described by a κO,κN chelate mode toward Sn. All complexes displayed bis(benzoxazolyl)phenolic moieties close to planar; the least planar system was observed in 4 that was also studied by DFT methods. Graphical abstract

Crystal structure of 2-(2-amino-phen-yl)-1,3-benzoxazole.

The two molecules of 2-(2-aminophenyl)-1,3-benzoxazole in the asymmetric unit feature an intramolecular N—H⋯N hydrogen bond, which closes an S(6) ring and therefore establishes a syn relationship for the N atoms. In the crystal, molecules are linked by N—H⋯N hydrogen bonds, generating [100] chains containing alternating A and B molecules.

A flexible access to highly functionalised boronates

The radical addition of various xanthates to allyl or vinyl boronates occurs smoothly in the presence of a small amount of lauroyl peroxide as initiator to give good yields of usefully functionalised boronates.