Synthesis and characterisation of a series of lamellar gallium and indium phosphonates and related compounds

A series of new layered gallium(III) and indium(III) phosphonates, phenylar sonates and phenylphosphinates have been prepared and characterised. The me thylphosphonate, phenylphosphonate and phenylarsonate derivatives of galliu m(III) possess a metal to ligand ratio of 1 : 1 and properties consistent w ith the formulation Ga(OH)(O3XR) (where X = P or As for R = C6H5, and where X = P for R = CH3), whereas the benzylphosphonate derivative forms the mon ohydrate Ga(OH)(O3XCH2C6H5). H2O. The corresponding phosphinate derivative of gallium(III) has a metal to ligand ratio of 1 : 2 with the formulation G a(OH)(O2P(H)C6H5)(2). The gallium compounds all contain a hydroxo group bon ded to the metal, unlike the corresponding indium(III) compounds. The pheny lphosphonate and phenylarsonate derivatives of indium(III) have a 1 : 2 met al to ligand ratio and formula In(O3XR)(O2X(OH)R). H2O (where R = C6H5 or C H2C6H5 when X = P and R = C6H5 when X = As), where the ligand is present as both a mono- and di-anion. The methylphosphonate of indium(III) has the un expected formulation In-2(O3PCH3)(3). 2H(2)O whereas the indium(III) phenyl phosphinate compound is In(O2P(H)C6H5)(3). These compounds were characteriz ed by elemental analysis, thermal gravimetry, X-ray powder diffraction (XRD ) and solid state P-31/C-13 MAS NMR spectroscopy. Powder XRD measurements i ndicate these compounds contain layered solid state structures.