Mark J. Drewitt

Organically templated layered uranium(VI) phosphates: hydrothermal syntheses and structures of [NHEt3][(UO2)2(PO4)(HPO4)] and [NPr4][(UO2)3(PO4)(HPO4)2]

Two organically templated layered uranium( VI) phosphates have been prepared under hydrothermal conditions from U 3O 8 and H 3PO 4 using either NPr 4 + or NHEt 3 + ions as structure directing agents; both compounds have layered structures which contain infinite chains of edge-sharing [UO 7] pentagonal bipyramids cross linked by bridging [PO 4] tetrahedra to form two dimensional sheets of [(UO 2) n - (HPO 4) n–1 (PO 4)] m m– anions.

Modification of MCM-41 via ring opening of a strained[1]ferrocenophane

The walls of the mesoporous silicate MCM-41 can be functionalised with ferrocenyl end groups by reaction with an alkane solution of (1,1′-ferrocenediyl)dimethylsilane; the product is studied by solid-state NMR and EXAFS spectroscopies.

The first [2]cobaltocenophane and [2]metallocenophanium salts

A tetramethylethylene bridged ferrocene 1 and cobaltocene 3 are synthesised in two steps from 2-tert-butyl-6,6-dimethylfluvene. Both can be oxidised to the corresponding cations, 2 and 4, the single-crystal X-ray structures of which have been determined.

Synthesis and structures of organometallic derivatives of 1,2,3,4,5,6,7,8-octamethyl-1,5-dihydro-s-indacene

A new fused-ring compound 1,2,3,4,5,6,7,8-octamethyl-1,5-dihydro-s-indacene (H2L1) has been synthesized from p-xylene. Three transition-metal derivatives [Mn(η5-HL1)(CO)3], [Rh(η5-HL1)(η-C5Me5)]+[SbF6]− and [Cr(η6-H2L1)(CO)3] have been characterised: spectroscopic and crystallographic data for these compounds show the ligand system is strongly electron donating. Although H2L1 is readily deprotonated to the monoanion by potassium metal or potassium hydride, surprisingly we have been unable to form (L1)2. The crystal structure of [K]+[HL1]−·18-crown-6 reveals the potassium ion to be sandwiched between the crown ether (1,4,7,10,13,16-hexaoxacyclooctadecane) and the (HL1)− anion.

Unusual reactivity and isomerisation in dicobalt s-indacene complexes

Di-{Co(Cp)} derivatives of But4-s-indacene (Ic′) have been prepared, they exist as both cis and trans isomers which can interconvert in solution; the solution electrochemistry of these complexes show that these bimetallic complexes can exhibit up to four redox events; unusually, attempted oxidation by a protic oxidising agent of (CoCp)2Ic results in attack at the central carbons of the indacene rings.

New strongly coupled dinuclear metal centres in organometallic s-indacene complexes

The complexes cis-[{Fe(CO) 3 } 2 L] and cis-[{Co(CO) 2 } 2 L] are prepared from 1,3,5,7-tetra-tert-butyl-s-indacene; in solution, the diiron complexes exhibit very strong electron–electron coupling between iron centres as evidenced by a 810 mV separation between the 0/+ and +/2+ redox waves.

Hydro(solvo)thermal synthesis and structure of a three-dimensionalzinc fluorophosphate:Zn2(4,4′-bipy)(PO3F)2

A new three-dimensional zinc fluorophosphate is prepared by using hydro(solvo)thermal conditions with ZnO, (HF) x ·py H 3 PO 4 and 4,4′-bipyridyl; the single-crystal structure is determined.

Silicon-bridged bis(cyclohexadienyl) iron complexes: the first structurally characterised [14]ferrocenophane

Reaction of the Me2Si bridged bis(6,6-dimethylcyclohexadienyl) dianion with FeCl2·1.5THF gives mono-, di- and tetrametallic complexes; {[Me2Si(DMCh)2]Fe}4 is the first crystallographically characterised [14]metallocenophane.