Some Semicarbazone Complexes of Titanium(IV) and Zirconium(IV)

TiIV Complexes of Redox‐Active Schiff Bases

“…Such ML 2 complexes have been previously reported for Ge IV and Zr IV [18,24] but without crystal structures. Only two examples of crystal structures that show similar salicylidene-2-aminothiophenol Schiff-base ligands coordinated to the same metal centre were reported for Ni IV [25] and Ti IV .…”

“…H 2 VI is also new, although the methyl analogue has been reported, [16] and it was selected to possibly accommodate two Ti centres. All of the ligands were prepared by the condensation of substituted salicylaldehydes with 2-aminothiophenol, and it has long been recognized [11,12,15,17,18] that these reactions can lead to three products, which depends on the reaction conditions, that have been identified mainly based on IR and elemental analyses as the anil (A), thiazoline (B), or thiazole (C) forms (Scheme 4).…”

Titanocene derivatives of purine and adenine. Synthesis and characterization of reaction products with (η5-C5H5)2Ti(CO)2, (η5-C5H5)2TiCl, and (η5-C5H5)2TiCl2

“…There are strong indications here, from ir and ms results for 8, that the amino group is involved in inter-or intra-molecular chelation in the solid state, possibly with titanium. Seemingly, saturated penta-coordinated titanium(1V) complexes are rare but have Structures been previously reported (24,25). Crystallographic measurements for 7 show that the molecule contains a bent-cycle metallocene unit to which the deprotoAcknowledgments nated purine ligand is bonded through the N9 nitrogen (30).…”

“…The reaction of 3 with the monoanions of chelating heterocyclic rings (XL), such as salicylaldimine and mercaptoquinazole, are reported to give mono or disubstitution compounds of the type C~~T~'~C I~( X L )~-~, where ir spectroscopic data seem to indicate that an additional dative bond from the bidentate ligand is also involved in the metal bonding in these complexes (24,25). Exchange of a chloride by an amino group occurs in liquid ammonia in the presence of excess amine (NH2R) to give the Cp2TiCl(NHR)-NH2R metallocene and the corresponding hydrochloric ammonium salt (26).…”