摘要 : New mononuclear titanium and zirconium imido complexes [M(NR)(R'_2calix)] [ M = TI, R' = Me, R = tBu (1) R = 2,6-C_6H_3Me_2 (2), R = 2,6-C_6H_3iPr_2 (3), R = 2,4,6-C_6H_2Me_3 (4); M = Ti, R' = Bz, R = tBu (5), R = 2,6-C_6H_3Me_2 (... 展开 New mononuclear titanium and zirconium imido complexes [M(NR)(R'_2calix)] [ M = TI, R' = Me, R = tBu (1) R = 2,6-C_6H_3Me_2 (2), R = 2,6-C_6H_3iPr_2 (3), R = 2,4,6-C_6H_2Me_3 (4); M = Ti, R' = Bz, R = tBu (5), R = 2,6-C_6H_3Me_2 (6), R = 2,6-C_6H_3iPr_2 (7); M = Zr, R'=Me, R = 2,6-C_6H_3iPr_2 (8)] supported by 1,3-diorganyl ether p-tert-butylcalix[4]arenes (R'_2calix) were prepared in good yield from the readily available complexes [MCl_2(Me_2calix)], [Ti(NR)Cl_2(py)_3], and [Ti(NR)Cl_2)(NHMe_2)_2]. The crystallographically characterised complex [Ti(NtBu)(Me_2calix)] (1) reacts readily with CO_2, CS_2, and p-tolyl-isocyanate to give the isolated complexes [Ti{N(tBu)C(O)O}(Me_2calix)] (10), [{Ti(mu-O)Me_2calix)}_2] (11), [{Ti(mu-S)(Me_2calix)}_2] (12), and [Ti{N(tBu)C(O)N(-4-C-6H_4Me)}(Me_2calix)] (13). In the case of CO_2 and CS_2, the addition of the heterocumulene to the Ti-N multiple bond is followed by a cycloreversion reaction to give the dinuclear complexes 11 and 12. The X-ray structure of 13·4(C_7H_8) clearly establishes the N,N'-coordination mode of the ureate ligand in this compound. Complex 1 undergoes tert-butyl/arylamine exchange reactions to form 2,3, [Ti(N-4-C_6H_4Me)(Me_2calix)] (14), [Ti(N-4-C_6H_4Fc)(Me_2calix)] (15) [Fc = Fe(eta~5-C_5H_5)(eta~5-C_5H_4)], and [{Ti(Me_2calix)}_2{mu-(N-4-C_6H_4)_2CH_2}] (16). Reaction of 1 with H_2O, H_2S and HCl afforded the compounds [{Ti(mu-O)(Me_2calix)}_2] (11), [{Ti(mu-S)(Me_2calix)}_2] (12), and [TiCl_2(Me_2calix)] in excellent yields. Furthermore, treatment of 1 with two equivalents of phenols results in the formation of [Ti(O-4-C_6H_4R)_2calix)] (R = Me 17 or tBu 18), [Ti(O-2,6-C_6H_3Me_2)_2(Me_2calix)] (19) and [Ti(mbmp)(Me_2calix)] (20; H_2mbmp = 2,2'-methylene-bis(4-methyl-6-tert-butyl-phenol) or CH_2({CH_3}{C_4H_9}C_6H_2OH)_2). The bis(phenolate) compounds 17 and 18 with para-substituted phenolate ligands undergo elimination and/or rearrangement reactions in the nonpolar solvents pentane or hexane. The metal-containing product of the elimination reactions are dinuclear complexes [{Ti(O-4-C_6H_4R)(Mecalix)}_2] [R = Me (23) or tBu (24)] where Mecalix = monomethyl ether of p-tert-butylcalix[4]arene. The products of the rearrangement reaction are [Ti(O-4-C_6H_4Me)_2 (paco-Me_2calix)] (25) and [Ti(O-4-C_6H_4Bu)_2(paco-Me_2calix)] (26), in which the metallated calix[4]arene ligand is coordinated in a form reminiscent of the partial cone (paco) conformation of calix[4]arene. In these compounds, one of the methoxy groups is located inside the cavity of the calix[4]arene ligand. The complexes 24, 25 and 26 have been crystallographically characterised. Complexes with sterically more demanding phenolate ligands namely 19 and 20 and the analogous zirconium complexes [Zr(O-4-C_6H_4Me)_2(Me_2calix)] (21) and [Zr(O-4-2,6-C_6H_3Me)_2(Me_2calix)] (22) do not rearrange. Density functional calculations for the model complexes [M(OC_6H_5)_2(Me_2calix)] with the calixarene possessing either cone or partial cone conformations are briefly presented. 收起