Michael Q Dequeant | PubMed Health

PubMed2005

One-dimensional supramolecular assemblies based on a Re2(III,III) synthon and their solid-state phosphorescence.

Reactions between Re2(DMBA)4(NO3)2 (1; DMBA is dimethylbenzamidinate) and a bidentate dianion, either tungstate (WO4(2-)) or terephthalte (1,4-(O2C)2C6H4(2-)), resulted in the one-dimensional coordination polymers [Re2(DMBA)4(mu-O,O'-WO4)](infinity) (2) and [Re2(DMBA)4(mu-O,O'-1,4-(O2C)2C6H4)](infinity) (3), respectively. Both polymers display phosphorescence from a 3(delta --> delta*) state, which is significantly blue shifted from the phosphorescence previously observed for Re2(DMBA)4Cl2 type compounds.

Journal Article↗

PubMed2004

Dirhenium paddlewheel compounds supported by N,N'-dialkylbenzamidinates: synthesis, structures, and photophysical properties.

Dirhenium(III,III) compounds Re2(DMBA)4Cl2 (1, DMBA=N,N'-dimethylbenzamidinate) and Re2(DEBA)4Cl2 (2, DEBA=N,N'-diethylbenzamidinate) were synthesized via molten reactions between Re2(OAc)4Cl2 and the corresponding amidine. Re2(DMBA)4(NO3)2 (3) was obtained through reacting Re2(DMBA)4Cl2 with AgNO3. Single crystal X-ray diffraction studies revealed that the Re-Re distances in compounds 1-3 are 2.212(1), 2.217(1), and 2.173(1) A, respectively, which are consistent with the presence of a Re-Re quadruple bond. Voltammetric studies revealed that compound 2 exhibits two quasireversible couples, an oxidation and a reduction, and an irreversible reduction, while compound 1 displays irreversible couples at similar potentials. The three complexes exhibit 1deltadelta* absorption as a shoulder at approximately 440 nm (epsilon approximately 1500 M(-1) cm(-1)). Upon excitation of solid samples or CH2Cl2 solutions of 2 with visible light, emission is observed at 824 nm (77 K) and 833 nm (298 K), respectively. The luminescence is assigned as arising from the 3deltadelta* excited state.

Benzamides↗