ChemInform Abstract: Synthetic and Spectroscopic Studies of Phosphoranides (PR(CN)2X)- and the Crystal and Molecular Structure of (NEt4)(PPh(CN)2Cl).

ChemInform ◽  
1990 ◽  
Vol 21 (19) ◽  
Author(s):  
R. M. K. DENG ◽  
K. B. DILLON ◽  
W. S. SHELDRICK
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Spectroscopic Studies

Group 6 metal carbonyl complexes of tridentate olefinic tertiary diphosphines. Crystal and molecular structure of {(E)-1,3-Bis[2-(diphenylphosphino)phenyl]-propene}tricarbonyltungsten(0),W(CO)3 {(E)-o-Ph2PC6H4CH=CHC6H4PPh2-o}

1980 ◽  
Vol 33 (6) ◽  
pp. 1261 ◽  
Author(s):  
MA Bennett ◽  
S Corlett ◽  
GB Robertson ◽  
WL Steffen
Keyword(s):  
Molecular Structure ◽  
Double Bond ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Metal Carbonyl ◽  
Free Ligand ◽  
Spectroscopic Studies ◽  
Carbonyl Complexes ◽  
X Ray Diffraction ◽  
Olefinic Double Bond

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).

Structural and spectroscopic studies of transition metal nitrite complexes. IV. Crystal structure and spectra of cis-Aquabis[N,N-dimethyl(ethane-1,2-diamine)]-nitronickel(II) perchlorate

1981 ◽  
Vol 34 (10) ◽  
pp. 2085 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Lower Energy ◽  
Crystal And Molecular Structure ◽  
Visible Region ◽  
Spectroscopic Studies ◽  
Charge Transfer Transition ◽  
Lower Energy Band ◽  
Ligand Charge Transfer ◽  
Vibrational Progression ◽  
Metal Ligand

The crystal and molecular structure of the complex cis-aquabis[N,N-dimethyl(ethane-l,2-diamine)]- nitronickel(11) perchlorate is reported and the stereochemistry is compared with those observed for other nickel nitrite complexes formed by substituted amines. The electronic spectrum of the complex in the visible region is unusual, showing bands with maxima at 17750 and 21000 cm-1. The latter peak consists of a poorly resolved vibrational progression having an interval of c.600cm-1. While the lower energy band is assigned to the second spin-allowed 'd-d' transition of an octahedral nickel(11) complex, it is suggested that the band at 21000 cm-1 is due either to a metal → ligand charge-transfer transition, or to an internal n(O)→ π* nitrite transition.

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