Selenophene molecular structure

Selenophene, bis(TV-chlorothioimino)-molecular structure, 4, 939 Selenophene, 2-bromo-mercuration, 4, 946 Selenophene, 3-bromo-lithiation, 4, 949 synthesis, 4, 955 Selenophene, 3-bromo-2-lithio-synthesis, 4, 955 Selenophene, bromonitro-debromination, 4, 78 synthesis, 4, 955 Selenophene, 2-chloromethyl-solvolysis, 4, 952 Selenophene, 3-cyano-synthesis, 4, 955 Selenophene, deutero-deuterium exchange, 4, 949 Selenophene, 2,5-diacyl-3,4-dihydroxy-synthesis, 4, 964... 

Selenophene, 2-methylmercapto-conformation, 4, 944 Selenophene, 2-nitro-mercuration, 4, 946 Selenophene, 2-phenyl-irradiation, 4, 42, 946 mass spectra, 4, 942 Selenophene, 3-phenyl-mass spectra, 4, 942 Selenophene, tetrachloro-applications, 4, 971 reactions, 4, 955 synthesis, 4, 963 Selenophene, tetrahydro-conformation, 4, 34, 944 IR spectra, 4, 942 mass spectra, 4, 24, 943 molecular structure, 4, 938 NMR, 4, 10, 13 reactions, 4, 88, 958 ring strain, 4, 28 synthesis, 4, 118, 962, 968 Selenophene, tetraphenyl-synthesis, 4, 118, 962, 964 Selenophene, 2-thienyl-... 

NMR using liquid crystal solvents is now a well-established tool for the investigation of molecular structure. Selenophene was studied in a liquid crystal composed of sodium sulfate, decanol, deuterium oxide, and sodium decylsulfate.12 The refined direct couplings were obtained iteratively with the help of a computer. The ratios of the interproton distances were calculated from the direct couplings and found to be in good agreement with corresponding values calculated from the microwave data. 

A consideration of the results of molecular structural determinations of furan,194 pyrrole,196 thiophene,196 and selenophene197-198 shows that bond alternation as exemplified by the ratio (R) of the C-2-C-3 to C-3-C-4 bond lengths decreases in the order, furan (R = 0.950), selenophene (R = 0.956), pyrrole (R = 0.959), and thiophene (R=0.964). Whether this corresponds to an aromaticity scale,189 considering that the bond angles at the heteroatom are widely divergent, is a matter for debate. The X-ray structure determination199 of 1,2,5-triphenylphosphole is discussed later. 

The characterization by ab initio molecular orbital theory of chalcogen isosteres of benzene <88JA4204> has allowed the prediction of structures with a precision of 0.04 A for the bonds and 2° for the angles. In this approach, the selenophene series shows important delocalization. New theoretically derived and energy-based criteria for aromaticity were proposed <90IJQ843,90PHC(2)50>. 

Much work has been devoted to the formation of complexes where selenophene acts as a ligand. For example, with first row transition metals selenienylthienylmethane forms stable molecular species <83MI 2l3-05>. The effect of substitution of either cyclopentadienyl or selenophene rings on the structure of if - and f/ -selenophene (sel) complexes Cp(CO)2Re(sel) has been discussed <91JA5651>. 

C. Wang, A. Ellern, J. Y. Becker and J. Bernstein, New angular molecular donor containing two tetrathiafulvalene (TTF) units fused to selenophene synthesis. X-ray structure, cyclic voltammetry and conducting charge transfer complex with TCNQ, Adv. Mater., 1, 644-646 (1995). 

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