Molecular zinc phosphonates:: synthesis and X-ray crystal structures of [{(ZnMe)4(THF)2}{tBuPO3}2] and [{(ZnEt)3(Zn(THF))3}{tBuPO3}4{μ3-OEt}]

The reactions of zinc alkyls with tert-butylphosphonic acid in 2 : 1 and 1 : 1 molar ratios afforded [{(ZnMe)(4)( THF)(2)}{tBuPO(3)}(2)] (2) and [{(ZnEt)(3)(Zn(THF))(3)}{tBuPO(3)}(4){mu(3)-OEt}] (3), respectively. Compounds 2 and 3 have been fully characterised by means of spectroscopic and analytical methods. Single-crystal X-ray diffraction studies revealed that zinc phosphonates 2 and 3 are tetra- and hexa-nuclear, respectively. This is in contrast to the dodecanuclear zinc phosphonate [{Zn-2(THF)(2)(ZnEt)(6)Zn-4(mu(4)-O)}{(tBuPO(3))(8)}] (1) obtained in a 1.5 : 1 reaction between zinc alkyls and tBuP(O)(OH)(2).