Photochemical synthesis and electron spin resonance characterisation of stable trivalent metal alkyls (Si, Ge, Sn) and amides (Ge and Sn) of Group IV elements

The reaction of MCl2(M = Ge or Sn) or Si2Cl6 with R1Li or (R22N)Li [R1=(Me3Si)2CH, R2= Me3Si] and subsequent irradiation affords the stable metal-centred radicals R13Si·, R13M·, or (R22N)3M·(e.g. R13Ge· has t½ > 4 months in C6H6 at 20 °C), the solution e.s.r. spectra of which show well defined hyperfine splittings [e.g. for (R22N)3Ge·, a decet of septets, due to coupling with 73Ge (I= 9/2) and 14N (I= 1)].