A series of low-coordinate tin and lead cationic complexes have been synthesized using the bulky β-diketiminate ligand [{N(2,6- i Pr2C6H3)C(Me)}2CH]− (BDI) to stabilize the metal center. Two different routes to [(BDI)Sn]+[X]− and [(BDI)Pb]+[X]− were explored (X = B(C6F5)4, AlCl4, MeB(C6F5)3): abstraction of the chloride with a Lewis acid from (BDI)SnCl and (BDI)PbCl and abstraction of a methyl group with a borane from (BDI)SnMe and (BDI)PbMe. The crystal structures of the tin and lead cations were determined; in both, solvent molecules were found to coordinate to the metal center. In the case of [(BDI)Pb]+[B(C6F5)4]−, a dichloromethane molecule was found. Density functional theory (DFT) calculations showed that this could be due to crystal packing. In the case of [(BDI)Sn]+[MeB(C6F5)3]−, an ether molecule was coordinated to the tin metal center. DFT calculations revealed a significant energy gain for the coordinated ether as opposed to the free molecules.

The reaction of isophthaloyl chloride and methyl-bis(trimethylsilyl)phosphane under mild conditions affords high yields of m-{-C(O)-C(6)H(4)(C(O)PMe)}(2) (1,10-dimethyl-1,10-diphospha-[3.3]-metacyclophane-2,9,11,18-tetraone): the first example of a diphosphametacyclophane.

Aroylphosphanes: base-free synthesis and their coordination chemistry with platinum-group metals

No abstract

The group 14 chloropropargyls R3EC ≡ CCH2Cl (R3E = (n)Bu3Sn, Ph3Sn, Me2PhSi, (i)Pr3Si, (n)Pr3Si, (n)Bu3Si), obtained by a modified literature procedure, react with LiPPh2 to afford the novel propargyl phosphanes Ph2PCH2C ≡ CER3 in high yield, as viscous oils; (Me3Si)2PCH2C ≡ CSiPhMe2 is similarly obtained from LiP(SiMe3)2. In contrast, the reaction of PhC[triple bond, length as m-dash]CCH2MgCl with ClP(NEt2)2 fails to produce a comparable propargyl phosphane, but generates preferentially (>70%) the novel phosphinoallene (Et2N)2PC(Ph) = C = CH2, which is characterised spectroscopically, and through its reaction with HCl. The coordination chemistry of representative phosphanes is explored with respect to platinum and palladium for the first time.