Chloromethane, bond angles

Four examples of dipole moments are instructive. First, the dipoles for chloromethane and dichloromethane are 1.87D and 1.60D, respectively. Although two chlorine-carbon bonds are present in the latter, the dipole is not along either but rather bisects the angle between them. This is illustrated schematically using the stylized arrow with its positive end in the form of a cross. The orientation question is shown clearly in the rigid dichlorobenzene framework. The dipole is 2.13D for the ortho-isomer and 0D when the dipoles exactly oppose each other. 

The C—Cl bond in the lowest singlet state of chlorocarbene of 169.61(25) pm is by about 9 pm shorter than that in chloromethane and this shortening is very similar to that in the fluorinated analogues [130.5(6) vs 139.1(1) pm]. Again, the biradical is strongly bent with a C1CH angle of 101.4°. A similarly short C—Cl bond has been determined for the chloromethyl radical [169.1(4) pm]. 

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