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The reaction of the neutral diphosphanide [((Cl)Im(Dipp))P-P(Cl)(Dipp)] (6) ((Cl)Im(Dipp) = 4,5-dichloro-1,3-bis(Dipp)-imidazol-2-yl; Dipp = 2,6-di-iso-propylphenyl) with methyl triflate (MeOTf) leads to the formation of cationic diphosphane [((Cl)Im(Dipp))(Me)P-P(Cl)(Dipp)](+) (8+) in a stereoselective methylation. In contrast, reacting with the Lewis acid GaCl3 yields cationic diphosphene [((Cl)Im(Dipp))P=P(Dipp)](+) (7+), which is explained by a low P-Cl bond dissociation energy. The significantly polarized P=P double bond in 7+ allows for its utilization as an acceptor for nucleophiles - the reaction with Cl(-) regenerates diphosphanide and the reaction with PMe3 gives cation [((Cl)Im(Dipp))P-P(PMe3)(Dipp)] (9+). In depth DFT investigation provides detailed insights into the bonding situation of the reported compounds.

The FLP-mesityl azide addition products 5, formed by FLP-addition to the terminal azide nitrogen atom, undergo N-N bond cleavage in an unusual variant of the Staudinger reaction upon thermolysis or photolysis to give an internally borane stabilized [P]=NH phosphinimine and a dimethylindazole derivative.

A methylzirconocene cation (with a [B(C(6)F(5))(4)](-) counterion) transfers a methyl cation equivalent to diphenylphosphino-alkynes to generate (η(2)-alkyne)ZrCp(2) complexes bearing the [RC≡CPPh(2)Me](+) ligand. Two examples of the PMe(3) ligand stabilized [(Me(3)P)Cp(2)Zr(η(2)-RC≡CPPh(2)Me)(+)][B(C(6)F(5))(4)(-)] salts were characterized by X-ray diffraction.

We report a convenient and smooth protocol for the high-yielding synthesis of a triphosphane and an iso-tetraphosphane from a readily accessible tri(pyrazolyl)phosphane. The products are obtained from a one-pot reaction at room temperature and form complexes with the Fe(CO)(4)-fragment.

Voluminous amides were coupled with deactivated, sterically hindered aryl chlorides in excellent yields providing products, which have not been efficiently accessible by transition metal catalysis so far. Application of an unsymmetric bisphosphine ligand was critical for the high catalytic activity.

Reaction of the acetylene Mes(2)P-C≡C-Ar with B(C(6)F(5))(3) at rt gives a zwitterionic phosphirenium product, which reacts further at >100 °C to complete the 1,1-carboboration reaction., (This journal is © The Royal Society of Chemistry 2011)

Hydroboration of the electron poor phosphine (1-propenyl)P(C(6)F(5))(2) with Piers' borane [HB(C(6)F(5))(2)] gave the geminal frustrated Lewis pair (C(6)F(5))(2)P-CH(Et)-B(C(6)F(5))(2). It undergoes 1,2-addition reactions to an alkene and an alkyne and to the C=N bond of an isocyanate. With mesityl azide it undergoes a 1,3-addition reaction.

The frustrated Lewis pair Mes(2)P-CH(2)CH(2)-B(C(6)F(5))(2) reacts with excess 6,6-dimethylpentafulvene to yield a P/B-Lewis pair addition product to an elusive pentafulvene [6 + 4] cycloaddition dimer. This observation may open a new field of utilization of frustrated Lewis pair chemistry.

The frustrated Lewis pair P(o-tolyl)(3)/B(C(6)F(5))(3) reacts with 1,7-octadiyne by acetylene C-C coupling to yield the zwitterionic product 2a. In contrast, the P(o-tolyl)(3)/B(C(6)F(5))(3) Lewis pair reacts with 1,6-heptadiyne by a sequence involving 1,1-carboboration of a terminal acetylene to eventually yield the heterocyclic product 4.

Bis(alkynyl)silanes (1a,b) react with bis(pentafluorophenyl)-borane to 3-boryl-2,5-bis(trimethylsilyl) substituted siloles 3a,b. Subsequent irradiation of 3 with Pyrex filtered UV light resulted in the complete conversion to the new 5-boryl-2,3-bis(trimethylsilyl) substituted siloles 4a,b.

Addition of B(C(6)F(5))(3) to an alpha-dimethylamino-o-vinylferrocenophane system gives a frustrated Lewis pair that undergoes intramolecular 1,2-N-B addition to the alkene.

Nitrile insertion into a zirconacycloallenoid complex leads to the formation of a seven-membered ring product with an attached boratirane unit.

Acylhydrazones of 2,3-dihydroxybenzaldehyde are easily accessible and afford heterodinuclear helicates; the self-assembly is specific when the resulting coordination compounds are neutral in charge.

The "frustrated Lewis pair" 1,8-bis(diphenylphosphino)naphthalene/B(C6F5)3 reversibly activates dihydrogen; it serves as an active catalyst for the hydrogenation of silyl enol ethers under mild reaction conditions.

A four-membered cyclic intramolecular phosphane-borane adduct activates dihydrogen to yield the respective ethylene-bridged zwitterionic phosphonium-hydridoborate system, which reduces benzaldehyde.

Three novel 2-carboxamide-8-hydroxyquinoline derivatives wrap helically around trivalent lanthanide ions to form monometallic 3 : 1 complexes possessing strong NIR emission.

The extension of Robson-type ligands from dinucleating based on 2,6-diformylphenol to trinucleating based on 2,7-diformyl-1,8-naphthalenediol is demonstrated by the synthesis, structural and magnetic characterization of the first trinuclear Cu(II) complex using a 1,8-naphthalenediol derived ligand.

The first organometallic clusters of mixed hydrazide/hydroxylamide clusters of zinc, [Zn(MeZn)(4)(HNNMe(2))(2)(ONEt(2))(4)] and {Zn(EtZn)(4)[HNN(CH(2))(5)](2)(ONEt(2))(4)} were synthesized in one-pot synthesis protocols from dialkylzinc solutions, substituted hydrazines and N,N-diethylhydroxylamine; competing for the Zn atoms, the different binding properties of hydrazide and hydroxylamide ligands in these heteroleptic clusters are discussed.

Bis(cyclopropylethynyl)zirconocene shows a bisected conformation in the crystal: the magnitude of the stabilizing conjugation of the Cp2Zr Lewis acid centre with the cyclopropyl substituent across the connecting C[triple bond]C triple bond is assessed by DFT calculations and a comparison with a series of cationic organic and organometallic reference systems.

The 21,23-dithia and 21-thia analogues of phlorins and mono-functionalized thiaphlorins were synthesized using easily available precursors and the mono-functionalized thiaphlorins were used further to synthesize the first examples of three covalently linked thiaphlorin-porphyrin dyads.

A new class of non-mesomerically stabilized, unbranched, configurationally stable lithiated alpha-thiocarbanion has been synthesized and its stereospecific reactions with several electrophiles were investigated.

Two hydrogen-bonds from geometrically constrained OH groups to coordinated oxygen donors shift the reduction potential of a Cu(II) complex by +270 mV as compared to the structurally analogous reference complex missing the OH groups.

The tartaric acid derived bis(beta-diketonate) ligand L affords either 2:3 or 3:2 ligand:metal complexes with nickel(II) ions depending on the stoichiometry of the components; the two complexes possess different electronic and geometric properties.

The diphenyl-ansa-zirconocene complex 2 adds HB(C6F5)2 at the C=C double bond of its pendent Cp-allyl functional group to yield 3. During 3 days at room temperature the -B(C6F5)2 group takes part in an electrophilic substitution reaction at the adjacent Cp-ring to form 5 with formation of one equivalent of benzene. Complex 5 was characterized by X-ray diffraction.

A huge molecular tetrahedral complex forms quantitatively by self-assembly from four ligands L-H6 and four titanium(IV) ions; in the solid state it encapsulates four [K(DIMF)3]+ units in its interior.

Chiral tetraketone ligands are obtained by Claisen-type condensation of 4-bromoacetophenone with the acetone ketal of L-tartraic acid diethylester and lead with gallium(III) or iron(III) ions in self-assembly processes to dinuclear helicate-type cryptands which are able to bind lithium cations.

The molybdenum pentachloride-mediated oxidative coupling of iodo-substituted electron rich benzenes without the loss of the iodo-substituents is reported. The presented methodology is an environmentally friendly alternative to known thallium(III)- and lead(IV)-reagents. Even 2,2',6,6'-tetraiodobiphenyl derivatives are easily accessible.