Dimethyl 3,3'-diphenyl-2,2'-[(S)-thio-phene-2,5-diylbis(carbonyl-aza-nedi-yl)]dipropano-ate.

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 65.8 (3) and 63.5 (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 0.277 (12) and 0.723 (12). Inter-molecular N-H⋯O hydrogen bonding is present in the crystal structure.

5-(Methoxy-carbon-yl)thio-phene-2-carboxylic acid.

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 3.1 (4) and 3.6 (4)°, respectively. In the crystal structure, mol-ecules are connected by classical inter-molecular O-H⋯O hydrogen bonds, forming centrosymmetric dimers.

Heterovalent-Doping-Enabled Efficient Dopant Luminescence and Controllable Electronic Impurity Via a New Strategy of Preparing II-VI Nanocrystals.

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.