The reactions of the metal amides [Ti(NMe,),], [Fe{N(SiMe3)2)3], and [ ( C O { N ( S~M~, )~)~)~] with p-tert-butylcalix[4]areneH4 (1) have resulted in the isolation and structural characterization of the first three a-bonded transition-metal derivatives of a calixarene. Complete exchange of the four -OH protons in 1 with [Ti(NMe,),] gives the complex [[Ti@tert-butylcalix[4]arene)12].6PhMe (2) as orange-red crystals. The conformationally mobile cone configuration of 1 acquires rigidity in the titanium complex which exists in a dimeric form with bridging through one of the ligand oxygens resulting in a distorted tetrahedral coordination at titanium. The reactions of 1 with [Fe(N(SiMe3)2)3] or [(Co(N(SiMe,),],),] are more complex and involve -SiMe, shifts from silylamide groups to a ligand oxygen giving, for iron, an unusual complex of formula
The synthesis and first structural characterization of crystalline primary and secondary mesitylphosphines PH2Mes (1) and PHMes2 (2) are described. Treatment of 1 and 2 with 1 equiv of n-BuLi affords the solvated lithium phosphides [Li(THF) 3PHMes] (3) and [|Li(OEt2)PMes2)2] (4), which possess previously uncharacterized structural types. A notable feature in the crystal lattice of 1 is the packing of PMes moieties into parallel layers. However, there are no strong interactions between these layers. In 2, the phosphorus center has a pyramidal geometry with bond angles near tetrahedral values. The X-ray crystal structure of 3 shows that it is the first structure of a lithium phosphide with a terminal phosphide group. The pyramidal geometry at phosphorus is in sharp contrast to the planar geometry found for lithium amides. Unlike that of 3, the structure of 4 is dimeric with solvated lithium atoms bridging two [PMes2]" moieties. The central Li2P2 core is essentially planar with the phosphorus centers having distorted tetrahedral geometries. A 3IP NMR study on the degree of solvation between ion pairs in various primary and secondary organophosphide complexes is also reported. Crystallographic data with Mo Ka radiation
The reaction of the metal amide (I) with the appropriate alcohols (II) and (IV) or the silanol (VII) affords the neutral dimeric or monomeric Co alkoxides (III), (VI), and (VIII) depending on the conditions shown in the scheme.
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