RESUMO
The asymmetric unit of the title compound, C(26)H(26)N(2)O(6)S, contains two independent mol-ecules; each has twofold symmetry with the S atom and the mid-point of the C-C bond of the thio-phene ring located on a twofold rotation axis. In the two mol-ecules, the terminal benzene rings are oriented at dihedral angles of 65.8â (3) and 63.5â (3)° with respect to the central thio-phene rings. The meth-oxy-carbonyl group of one mol-ecule is disordered over two positions with site-occupancy factors of 0.277â (12) and 0.723â (12). Inter-molecular N-Hâ¯O hydrogen bonding is present in the crystal structure.
RESUMO
In the title compound, C(7)H(6)O(4)S, a monoester derivative of 2,5-thio-phene-dicarboxylic acid, the carboxylic acid and the carboxylic acid ester groups are approximately coplanar with thio-phene ring, making a dihedral angle of 3.1â (4) and 3.6â (4)°, respectively. In the crystal structure, mol-ecules are connected by classical inter-molecular O-Hâ¯O hydrogen bonds, forming centrosymmetric dimers.
RESUMO
Substitutional heterovalent doping represents an effective method to control the optical and electronic properties of nanocrystals (NCs). Highly monodisperse II-VI NCs with deep substitutional dopants are presented. The NCs exhibit stable, dominant, and strong dopant fluorescence, and control over n- and p-type electronic impurities is achieved. Large-scale, bottom-up superlattices of the NCs will speed up their application in electronic devices.