title: Synthesis, structures and reactivity of group 4 hydrazido complexes supported by calix[4]arene ligands.
abstract: Reaction of TiCl(2)(Me(2)Calix) with 2 equiv of LiNHNRR' afforded the corresponding terminal hydrazido(2-) complexes Ti(NNRR')(Me(2)Calix) (R = Ph, R' = Ph (1) or Me; R = R' = Me (3)) which were all structurally characterized. The X-ray structure of Ph(2)NNH(2) is reported for comparison. Compound 1 was also prepared from Na(2)[Me(2)Calix] and Ti(NNPh(2))Cl(2)(py)(3). Reaction of ZrCl(2)(Me(2)Calix) with 2 equiv of LiNHNR(2) afforded only the bis(hydrazido(1-)) complexes Zr(NHNR(2))(2)(Me(2)Calix) (R = Ph or Me). Treatment of Ti(NNMe(2))(Me(2)Calix) (3) with MeI gave the zwitterionic hydrazidium species Ti(NNMe(3))(MeCalix) (6) via a net isomerization reaction which was found to be catalytic in MeI. The corresponding reaction of 3 with CD(3)I gave Ti(NNMe(2)CD(3))(MeCalix) (6-d(3)) with concomitant elimination of MeI. Reaction of 3 with 1 equiv of MeOTf gave [Ti(NNMe(3))(Me(2)Calix)][OTf] (7-OTf) which in turn reacted with (n)Bu(4)NI to form 6 and MeI. Addition of PhCHO to 3 gave the mu-oxo dimer [Ti(mu-O)(Me(2)Calix)](2) and benzaldehyde-dimethylhydrazone. Reaction of either 3 or 6 with (t)BuNCO gave the zwitterionic species Ti{(t)BuNC(NNMe(3))O}(MeCalix) (10) which has been crystallographically characterized. Compound 10 is the formal product of insertion of an isocyanate into the Ti=N(alpha) bond of a titanium hydrazide or hydrazidium species (Me(2)Calix or MeCalix = dianion or trianion of the di- or monomethyl ether of p-tert-butyl calix[4]arene, respectively).
authors.affiliation: Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Clulow
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Selby
authors.forename: Michael G
authors.initials: MG
authors.lastname: Cushion
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Schwarz
authors.forename: Philip
authors.initials: P
authors.lastname: Mountford
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D006834:Hydrazines / Q000138:chemical synthesis* / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D007700:Kinetics; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D010636:Phenols / Q000737:chemistry*; D011336:Probability; D013053:Spectrophotometry; D014961:X-Ray Diffraction
chemical_list: D006834:Hydrazines; D008024:Ligands; D010636:Phenols; C121325:calix(4)arene; D047250:Calixarenes