Eingegangen am 9. Dezember 1985 Durch Reaktion von Metallocen-dichloriden der IV. Nebengruppe M(q5-CsH4R)2C12 (R = H M = Ti, la; Zr, l b Hf, lc. R = CH3: M = Ti, Id) rnit aquimolaren Mengen der S,Nbzw. N,N'-Dilithium-Salze des o-Aminothiophenols oder o-Phenylendiamins konnen die Chelat-Komplexe M(q5-C5H4R)#C6H4NH) (R = H: M = Ti, 2a; Zr, 2 b Hf, 2c. R = CH3: M = Ti, 2d) und M(qs-CSH5)2(NHC6H4NH) (M = Ti, 3a; Zr, 3 b Hf, 3c) dargestellt werden. Die Struktur der Komplexe 2a -d rnit fiinfgliedrigen MSC2N-Chelatringen wird anhand ihrer temperaturvariablen 'H-NMR-Spektren diskutiert. Die Fragmentierung der Chelate 2a-d und 3a-c im Massenspektrum wird untersucht. New Metallacycles of Titanocene, Zuconocene, and Hafnocene Systems with S,N-and N,"-Coordinated Chelate Ligands By reaction of metallocene dichlorides of subgroup IV M($-C5H4R)2C12 (R = H: M = Ti, l a ; Zr, l b Hf, lc. R = CH3: M = Ti, l d ) with equivalent amounts of the S,N-or N,N'dilithium salts of o-aminothiophenol or o-phenylenediamine, respectively, M($-C5H4R)2(SC6H4NH) (R = H: M = Ti, 2a; Zr, 2b; Hf, 2c. R = CH3: M = Ti, 2d) and M($-CSH&(NHC6H4NH) (M = Ti, 3a; Zr, 3 b Hf, 3c) can be prepared as chelate complexes. The structure of the complexes 2a-d with five-membered MSCzN chelate rings is discussed on the basis of their temperature-variable 'H NMR spectra. The fragmentation of the chelates 2a-d and 3a-c is observed in the mass spectra.