Synthesis and IR and NMR spectroscopic studies of amino derivatives of oxo-, thio-, and selenopyrazole. Crystal and molecular structure of 1-phenyl-3-methyl-4-methylene-(N-8-aminoquinoline)-5-oxopyrazole

2000 ◽  
Vol 45 (5) ◽  
pp. 778-781 ◽  
Author(s):  
A. S. Antsyshkina ◽  
G. G. Sadikov ◽  
A. I. Uraev ◽  
O. Yu. Korshunov ◽  
A. L. Nivorozhkin ◽  
...  
1980 ◽  
Vol 33 (6) ◽  
pp. 1261 ◽  
Author(s):  
MA Bennett ◽  
S Corlett ◽  
GB Robertson ◽  
WL Steffen

The ligands (L) (E)-2,2'-bis(diphenylphosphino)stilbene, (E)-o-Ph2PC6H4CH=CHC6H4PPh2-o (bdps), (E)-1,3-bis[2-(diphenylphosphino)phenyl]propene, (E)-o-Ph2PC6H4CH=CHCH2C6H4PPh2-o (bdpp), and (E)-1,3-bis[2-(diphenylphosphino)phenyl]but-1-ene,( E)-o-Ph2PC6H4CH=CHCHMeC6- H4PPh2-o (bdpb), form complexes of general formula M(CO)3L (M = Cr, Mo, W). N.m.r. (1H, 13C and 31P) and i.r. data indicate that the metal atoms are octahedrally coordinated by mutually trans phosphorus atoms and the double bond of the olefinic tertiary diphosphines and by meridionally disposed carbonyl groups. Conformational isomers of the complexes of bdpb can be detected by n.m.r, spectroscopy, but there is no evidence for similar conformers in the corresponding complexes of bdps and bdpp. The crystal and molecular structure of W(CO)3(bdpp),0.5CH2C12 has been determined by single-crystal X-ray diffraction analysis. The crystals are triclinic, space group PI, with a 10.1 13(Z), b 13.820(2), c 14.512(3) A, α 76.24(1), β 88.08(1), γ 76.31(1)°. The structure, solved by the heavy-atom method and refined to a conventional R of 0.049 for 8418 diffractometer data, confirms the conclusions drawn from spectroscopic studies. The olefinic double bond of bdpp is attached symmetrically to the metal atom [W-C(olefin) 2.403(8), 2.387(9) Ǻ] and is roughly parallel to the P-W-P axis. The C=C bond length of 1.359(11) Ǻ is only slightly longer than that expected for the free ligand and is indicative of relatively weak metal-olefin back-bonding. Other important bond lengths are: W-P 2.450(2), 2.462(2) Ǻ and W-C(C0) 2.020(7), 2.024(7) Ǻ (CO trans to CO) and 1.971(7) Ǻ (CO trans to olefin).


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