On the structure and stability of electron deficient species derived from [Cr(CO)3(arene)]

被引:12
作者
McGrady, JE [1 ]
Dyson, PJ [1 ]
机构
[1] Univ York, Dept Chem, York YO10 5DD, N Yorkshire, England
关键词
molecular orbital; density functional; arene; chromium; carbonyl; mass spectrometry;
D O I
10.1016/S0022-328X(00)00345-4
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
Electron impact ionisation mass spectrometry has been used to study [Cr(CO)(3)(arene)], arene = C6H6, C6H4Me2-1,4, C6H2Me3-1,2,4.5 and C6Me6. Successive loss of CO ligands results in the production of electron-deficient complexes [Cr(CO)(3-x)(C6H6)](+) (where x=0 to 3). Analysis of these species using approximate density functional theory indicates that the loss of CO ligands stabilises high-spin states, the effect being more marked in the cationic species than in their neutral counterparts. The high-spin states also tend to have more symmetric structures than their low-spin counterparts. The calculated value of the second CO dissociation energy is lower than either the first or third, consistent with gas-phase data obtained by electron impact ionisation mass spectrometry, which consistently show more intense peaks for the [Cr(CO)(C6H6)](+) than for [Cr(CO)(2)(C6H6)](+). The loss of the second CO ligand results in a transition from a doublet to a sextet ground state, and the resultant substantial structural rearrangements may be responsible for the anomalously low dissociation energy. (C) 2000 Elsevier Science S.A. All rights reserved.
引用
收藏
页码:203 / 207
页数:5
相关论文
共 47 条
[1]   REACTIONS OF ATOMIC METAL-IONS WITH ALKYL-HALIDES AND ALCOHOLS IN THE GAS-PHASE [J].
ALLISON, J ;
RIDGE, DP .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1979, 101 (17) :4998-5009
[2]  
[Anonymous], RECENT ADV DENSITY 2
[3]  
BAERENDS EJ, 1999, ADF
[4]   17-ELECTRON METAL-CENTERED RADICALS [J].
BAIRD, MC .
CHEMICAL REVIEWS, 1988, 88 (07) :1217-1227
[5]   On the possible structures of Mn2(CO)8:: Theoretical support for an unprecedented asymmetric unbridged isomer [J].
Barckholtz, TA ;
Bursten, BE .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1998, 120 (08) :1926-1927
[6]   AN ABINITIO STUDY OF FE(CO)1, FE(CO)5, AND CR(CO)6 [J].
BARNES, LA ;
ROSI, M ;
BAUSCHLICHER, CW .
JOURNAL OF CHEMICAL PHYSICS, 1991, 94 (03) :2031-2039
[7]   New developments in matrix isolation spectroscopy [J].
Bondybey, VE ;
Smith, AM ;
Agreiter, J .
CHEMICAL REVIEWS, 1996, 96 (06) :2113-2134
[8]   A density functional study of open-shell cyclopentadienyl-molybdenum(II) complexes.: A comparison of stabilizing factors:: Spin-pairing, Mo-X π bonding, and release of steric pressure [J].
Cacelli, I ;
Poli, R ;
Quadrelli, EA ;
Rizzo, A ;
Smith, KM .
INORGANIC CHEMISTRY, 2000, 39 (03) :517-524
[9]  
ChamotRooke J, 1996, J MASS SPECTROM, V31, P199, DOI 10.1002/(SICI)1096-9888(199602)31:2<199::AID-JMS289>3.0.CO
[10]  
2-5