Internal dynamics in organometallic molecules: rotational spectrum of (CH3)3GeCl.

The microwave spectra of (CH(3))(3)(74)Ge(35)Cl and its isotopologues (CH(3))(3)(72)Ge(35)Cl and (CH(3))(3)(74)Ge(37)Cl have been studied in the frequency range from 3-24 GHz revealing the complex internal dynamics of this organometallic molecule with three internal rotors. The assignment of the complex spectrum has been facilitated by permutation-inversion theory and ab initio calculations. The V(3) barrier to internal rotation is determined to be 372.359(47) cm(-1). Furthermore, an analysis of the chlorine quadrupole coupling yields the description of the Ge-Cl bonding character which is estimated to be dominated by covalent contributions (46.5%) together with 37.6% ionic and 15.9% pi-bonding character. From isotopic substitution the Ge-Cl bond distance could be determined as 2.15198(97) Angstroms.