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We report a facile biomimetic sol-gel synthesis using the sponge phase formed by the lipid monoolein as a structure-directing template, resulting in high phase purity, mesoporous dysprosium- and gadolinium titanates. The stability of monoolein in a 1,4-butanediol and water mixture complements the use of a simple sol-gel metal oxide synthesis route. By judicious control of the lipid/solvent concentration, the sponge phase of monoolein can be directly realised in the pyrochlore material, leading to a porous metal oxide network with an average pore diameter of 10 nm.

The 2,6-dixylyl-4-phenylphosphabarrelene has been synthesised from the parent phosphinine and its properties as a ligand explored through the preparation and characterisation of the complexes W(CO)5(L), Re(CO)4(L)Cl, (η6-cymene)RuCl2(L), [(η5-Me3SiC5H4)Fe(CO)2(L)]PF6, Rh(1,5-COD)(L)Cl, Ir(1,5-COD)(L)Cl, and cis-Pt(L)2Cl2, where L = 4-phenyl-2,10-bis-(2,4-dimethylphenyl)-4H-1,4-ethenophospholine (xPB), cymene = 4-isopropyltoluene, η5-Me3SiC5H4= trimethylsilylcyclopentadienyl and 1,5-COD = 1,5-cyclooctadiene. The new complexes were characterised by spectroscopic and analytical techniques and, for [(η5-Me3SiC5H4)Fe(CO)2(L)]PF6and Ru(η6-cymene)(L)Cl2, by single-crystal X-ray structure determination. The coordination properties of the phosphabarrelene have been established and compared with analogous complexes of triarylphosphines and triarylphosphites. Most spectroscopic and structural indicators suggest that the phosphabarrelene has coordination behaviour similar to that of simple triarylphosphines such as PPh3. [ABSTRACT FROM AUTHOR]

A series of halo substituted triarylphosphinines have been synthesised and coordinated to tungsten(0) and rhodium(I) to give [(2-(2′-halo)-triarylphosphinine)W(CO)5] and [(2-(2′-halo)-triarylphosphinine)Rh(COD)Cl] respectively. The complexes have been examined by NMR and IR spectroscopy in an effort to elucidate the nature of the bonding between the phosphinines and the respective metal centre. The W(CO)5(L) systems reveal restricted C–C bond rotation as evidenced by temperature-dependent 31P{1H} NMR spectra. Thermodynamic barriers to the rotation are dependent upon the nature of the halide with ΔG‡values of 72.5 kJ mol−1and 50.8 kJ mol−1being obtained for the chloro- and fluoro-derivatives, respectively; activation barriers for the iodo- and bromo- derivatives were beyond the accessible temperature range of the NMR experiment. [ABSTRACT FROM AUTHOR]

A series of distorted octahedral Cr(iii) complexes containing tridentate S-, S/O- or N-donor ligands comprised of three distinct architectures: facultative {S(CH2CH2SC10H21)2 (L1) and O(CH2CH2SC10H21)2 (L2)}, tripodal {MeC(CH2SnC4H9)3 (L3), MeC(CH2SC10H21)3 (L4)} and macrocyclic {(C10H21)[9]aneN3 (L5), (C10H21)3[9]aneN3 (L6), with [9]aneN3 = 1,4,7-triazacyclononane} are reported and characterised spectroscopically. Activation of [CrCl3(L)] with MMAO produces very active ethylene trimerisation, oligomerisation and polymerisation catalysts, with significant dependence of the product distribution upon the ligand type present. The properties of the parent [CrCl3(L)] complexes are probed by cyclic voltammetry, UV-visible, EPR, EXAFS and XANES measurements, and the effects upon activation with Me3Al investigated similarly. Treatment with excess Me3Al leads to substitution of Cl ligands by Me groups, generation of an EPR silent Cr species (consistent with a change in the oxidation state of the Cr to either Cr(ii) or Cr(iv)) and substantial dissociation of the neutral S and S/O-donor ligands. [ABSTRACT FROM AUTHOR]

Some new bulky fluorinated diphosphines have been prepared and converted to palladium dichloride complexes that have been found to give increased regioselectivity and activity over other Pd–diphosphine systems when used as catalysts for hydroxycarbonylation of styrene. [ABSTRACT FROM AUTHOR]