Methanethiol, bond angle

Methanethiol, bond angles in, 20 dipole moment of, 39 electrostatic potential map of. 167 molecular model of, 20 pKa of, 604 structure of, 20... 

Methanethiol, CH3SH. (a) Lewis structure and (b) ball-and-stick model.The C—S—H bond angle is 100.3°, somewhat smaller than the tetrahedral angle of 109.5°. 

The functional group of a thiol is an —SH (sulfhydryl) group bonded to an sp hybridized carbon. Figure 10.4 shows a Lewis structure and a ball-and-stick model of methanethiol, CHjSH, the simplest thiol. The C—S—H bond angle in methane-thiol is 100.3°. By way of comparison, the H—S—H bond angle in H2S is 93.3°. If a sulfur atom were bonded to two other atoms by fully hybridized sp hybrid orbitals, bond angles about sulfur would be approximately 109.5°. If, instead, a sulfur atom were bonded to two other atoms by unhybridized 3p orbitals, bond angles would be... 

Alcohols and phenols have nearly the same geometry around the oxygen atom as water. The C-O-H bond angle is approximately tetrahedral (108.5° in methanol, for instance), and the oxygen atom is sp -hybridized. Thiols have a more compressed C-S-H bond angle (96.5° in methanethiol). 

Sulfur is most commonly encountered in biological molecules either in compounds called thiols, which have a sulfur atom bonded to one hydrogen and one carbon, or in sulfides, which have a sulfur atom bonded to two carbons. Produced by some bacteria, methanethiol (CH3SH) is the simplest example of a thiol, and dimethyl sulfide [(ChP S l is the simplest example of a sulfide. Both can be described by approximate sp3 hybridization around sulfur, although both have significant deviation from the 109.5° tetrahedral angle. 

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