Bent geometries, lanthanides

The structural picture is better clarified for the dichlorides (see Drake and Rosenblatt 1979 and references therein). Scandium dichloride is known to be linear (Dooh) as indicated by matrix IR isotope shifts and selection rules, while YCI2 is predicted to be bent (C2v configuration). The known lanthanide dichlorides SmCb, EuCl2 and YbCl2 are bent (C2v) and the Cl-R-Cl angles have been determined as 130 , 135 and 140 , respectively. Table 7 lists the vibrational frequencies of the dichlorides of Sm, Eu and Yb assigned on the basis of bent C2v geometry. 

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