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The crystalline lithium N, N′‐diorganoamidinates Li[PhC(NR)2] (1: R = c‐C6H11, 2: R = iPr) and Li[(CF3)3C6H2C(N‐c‐C6H11)2] (3) have been obtained by the reaction of phenyllithium or 2, 4, 6‐tris(trifluoromethyl)phenyllithium, resp., with diorganocarbodiimides R‐N=C=N‐R (R = c‐C6H11, iPr). These amidinates have been used for the synthesis of the homoleptic lanthanide(III) amidinates [PhC(N‐c‐C6H11)2]3Ln (4—6: Ln = Pr, Nd, Sm) and [PhC(NiPr)2]3Pr (7). Seven‐coordinate Lewis‐base adducts of the type [PhC(NSiMe3)2]3Ln(NCPh) (8, 9: Ln = Sm, Eu) have been prepared by addition of benzonitrile to the homoleptic precursors [PhC(NSiMe3)2]3Ln. The compounds 2 (as its THF adduct), 4, 6, 8 and 9 have been structurally characterized by single crystal X‐ray analyses.

Depending on the reaction conditions and the ionic radius of the lanthanide ion, tetraphenyldisiloxanediol, (Ph 2 SiOH) 2 O, reacts with [Ln{N(SiMe 3 ) 2 } 3 {LiCl(thf) 3 } 3 ] (Ln = Eu, Gd, Sm) to afford novel heterobimetallic rare earth disiloxanediolates, some of which can be regarded as 'inorganic lanthanide metallocenes'; a ring expanded uranium(vi) derivative, [U{Ph 2 Si(OSiPh 2 O) 2 } 2 {(Ph 2 SiO) 2 O}] 4, is formed upon treatment of uranocene, [U(h 8 -C 8 H 8 ) 2 ], with (Ph 2 SiOH) 2 O.

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Die IR‐ und Raman‐Spektren der Verbindungen OVCl2O–i‐C3H7, OVCl(O–i‐C3H7)2 und OV (O–i‐C3H7)3 sowie die IR‐, Raman‐, 1H‐NMR‐ und 13C‐NMR‐Spektren von OV(O–t‐C4H9)3 werden mitgeteilt. Aus den Spektren geht hervor, daß die Verbindungen als Gleichgewichtsgemische von Rotationsisomeren vorliegen. Für das Tri‐t‐butylorthovanadat im festen Zustand werden die zwischen den Rotationsisomeren auftretenden Enthalpiediefferenzen aus der Temperaturabhängigkeit der Ramanintensitäten abgeschätzt.