Physical and Theoretical Studies

6- C2B4H and 2,4-C2BsH7. In each case condensation reactions of the parent ion with itself are observed toother with loss of Hg. Proton transfer reactions of 

Rate constants and activation energies are reported from a kinetic study of the heterofunctional condensation of hydroxydimethylsilyl-m-carbaborane with RSiMcgCl (R=Me, Pr, CF3CH2CH2, CHgCl, or H), which proceeds by a mechanism close to Ss2. The reaction centre is equally sensitive to the induction and steric effects of the substituent R.  

Skatda, J. Rais, and M. Kyrs, /. Inorg. Nucl. Chem., 1979, 41, 1443. 

Gal chenko, E. P. Brykina, V. K. Pavlovich, V. N. Siryatskaya, and A. F. Zhigach, Dokl. Akad. Nauk SSSR Phys. Chem. 1979, 249, 1136. 

Manojlovic-Muir, K. W. Muir, and T. Solomun, J. Chem. Soc., Dalton Trans., 1980, 317. 

Macasek, S. Hermanek, and J. Plesek, Radiochem. Radioanalyt Letters, 1977, 29, 317. 

Macasek, L. Matel, and M. Kyrs, Radiochem. Radioanalyt. Letters, 1978, 35, 247. 

study has been carried out for carbaborane species 2,3-C2B4H8, 1,5-C2B3Hs, 1,6-C2B4H8, 2,4-C2B5H 1,2-C2BioHi2, 1,2-C2(CH2C0C2H5)- 

BioHii, 1,2-C2(CH2SC2H5)BioHii, and l,7-C2BioHi2. Four-co-ordinated carbon atoms in 1,5-C2B3H6 and l,6-C2B4He, which are bonded to two and three boron atoms respectively, resonate approximately 20 to 40 p.p.m. lower field than do five- or six-co-ordinated carbon atoms in higher carbaboranes. In general there 

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Comprehensive reviews of the chemistry of sydnones (1) have been published elsewhere, and a general discussion of this subject is not included here. Recent work on the photochemistry (Section IX), physical and theoretical studies (Section XI), and pharmacological activity (Section XII) of sydnones (1) is included in later sections. 

The molybdenum(II) carboxylates, Mo2(02CR)4, are key derivatives containing molybdenum-molybdenum quadruple bonds.1 First described by Wilkinson and coworkers in the early 1960s,2 they remain the key starting materials in (Mo2)4 + chemistry and they have been the objects of numerous physical and theoretical studies.1 The most commonly used method of preparation is the reaction between molybdenum hexacarbonyl and a carboxylic acid in an inert solvent such as 1,2-dichlorobenzene (DCB) [eq. (I)].3 Excellent yields of Mo2(02CR)4 can be obtained by... 

The syntheses, as well as physical and theoretical studies regarding the aromatic character of heterobenzenes, such as phosphabenzene " , arsabenzene and bismabenzene , have been extended also for stibabenzene . The benzenelike structure has been attributed to stibabenzene on the basis of experimental study and theoretical interpretation of the microwave spectra of SbCjH5, SbCjH5, ) -dideuterio SbC5H3D2 and 8-dideuterio SbC5H3D2 in the region 26.5-40.0GHz. 

Physical and Theoretical Studies of Alkylidyne Metal Complexes. 228... 

Table 3 Physical and theoretical studies on chromocene and dibenzenechromium...

Guided by the knowledge that the p-lactam antibiotics act by acylation, a number of physical and theoretical studies have been directed at the chemical reactivity of the strained p-lactam ring. It should be emphasized that these studies do not assume a uniform target. Rather they assume a mode of action that involves interaction between the p-lactam ring of the antibiotic and some functionality or functionalities at the target sites. 

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