Bonds r

Hendrickson (14,15] concentrated mainly on C-C bond-forming reactions because the construction of the carbon atom skeleton is the major task in the synthesis of complex organic compounds. Each carbon atom is classified according to which kind of atoms are bonded to it and what kind of bonds ([Pg.184]

Two efficient syntheses of strained cyclophanes indicate the synthetic potential of allyl or benzyl sulfide intermediates, in which the combined nucleophilicity and redox activity of the sulfur atom can be used. The dibenzylic sulfides from xylylene dihalides and -dithiols can be methylated with dimethoxycarbenium tetrafiuoroborate (H. Meerwein, 1960 R.F. Borch, 1968, 1969 from trimethyl orthoformate and BFj, 3 4). The sulfonium salts are deprotonated and rearrange to methyl sulfides (Stevens rearrangement). Repeated methylation and Hofmann elimination yields double bonds (R.H. Mitchell, 1974). 

Bond, R. (1990) Tire adhesion role of elastomer characteristics, in Supplementary Volume 2 of the Encyclopedia of Materials Science and Engineering, ed. Cahn, R.W. (Pergamon Press, Oxford) p. 1338. 

The chemistry of compounds which contain boron-boron bonds. R. J. Brotherton, Prog. Boron Chem., 1964,1,1-81 (189). 

C atom has one unpaired electron in each of its four sp hybrid orbitals and can therefore form four cr-bonds that point toward the corners of a regular tetrahedron. The C—C bond is formed by spin-pairing of the electrons in one sp hybrid orbital of each C atom. We label this bond hybrid orbital composed of 2s- and 2/t-orbitals on a carbon atom, and the parentheses show which orbitals on each atom overlap (Fig. 3.15). Each C—H bond is formed by spin-pairing of an electron in one of the remaining sp hybrid orbitals with an electron in a 1 s-orbital of an H atom (denoted His). These bonds are denoted cr(C2s/ Hls). 

In addition to forming different ways in which t/-orbitals can combine to form bonds, (b) Place the three types of d-d bonds—[Pg.256]

Electrophilic Additions to Carbon-Carbon Multiple Bonds R hydro-boration OR 0xdn% h J OH3 OR + HO r CH3... 

Bond, R.G., Straub, C.P. CRC Handbook of Environmental Control, 4 vols., CRC Press, Cleveland, 1973. 

Figure 3.19 Bent-bond representation of the double bond in ethene. The overlap of sp3 orbitals on each carbon atom produces to bend bond (r) orbitals.

Figure 3.20 (a) The cr-ir model of the C=C double bond, (b) Taking the sum and difference of these orbitals produces two bent bond (r) orbitals. 

Am. (a) The chlorine atoms are bonded to each other with a covalent bond. (h) The chlorine atoms are both bonded to the sulfur atom with covalent bonds, (r) The chlorine atoms are changed to Cl ions, and are bonded to the magnesium ion by ionic bonds. 

Figure 4. CSP-HPLC separation of the enantiomers of BaP dihydro- and tetrahydro- trans-7,8-diol and trans-9.10-diol. A column (4.6 mm ID x 25 cm) of y-aminopropylsilanized silica with ionically bonded (R)-N-(3,5-dinitrobenzoyl)phenylglycine was eluted with 18% (v/v) of ethanol/acetonitrile (2 1, v/v) in hexane at a solvent flow rate of 2 ml/min.(Reproduced with permission from Ref. 20.

G. Bond, R. B. Moyes, Application of Microwaves in Catalytic Chemistry in Microwave-Enhanced Chemistry Fundamentals, Sample Preparation and Applications. H. M. Kingston, S. J. Haswell (eds.), American Chemical Society, Washington, DC, 1997, p. 551, and references cited therein. 

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