Robert J Baker

• PhD
• Trinity College, Dublin at Trinity College Dublin

The solution structure of 1.0 M Uranyl Chloride has been determined by the EPSR modelling of a combination of neutron scattering and EXAFS data. The experimental data show an equilibrium in solution between [UO2(H2O)5]2+ and [UO2Cl(H2O)4]+ with a stability constant of 0.23 ± 0.03 mol-1 dm-3. A much smaller fraction of the neutral [UO2Cl2(H2O)3] ion...

The actinide (An) M4,5 edge high energy resolution X-ray absorption near edge structure (HR-XANES) and core-to-core 3d4f resonant inelastic X-ray scattering (3d4f RIXS) are becoming increasingly important for electronic structure and speciation studies of actinide materials. We applies these techniques to reveal bonding properties – reactivity rel...

Herein, a multi-technique study was performed to reveal the elemental speciation and microphase composition in altered granitic rock collected from the Krunkelbach Valley uranium (U) deposit area near an abandoned U mine, Black Forest, Southern Germany.

Computational modeling is an important aspect of the research on nuclear waste materials. In particular, atomistic simulations, when used complementary to experimental efforts, contribute to the scientific basis of safety case for nuclear waste repositories. Here we discuss the state-of-the-art and perspectives of atomistic modeling for nuclear was...

The structure of [TMEDAH2][B5O6(OH)4]2 is reported and hydrogen bonding gives a ‘brickwall’ type structure. This is a blue emitter in solution. Open image in new window

Herein, a multi-technique study was performed to reveal the elemental speciation and microphase composition in altered granitic rock collected from the Krunkelbach Valley uranium (U) deposit area near an abandoned U mine, Black Forest, Southern Germany. The former Krunkelbach U mine with 1–2 km surrounding area represents a unique natural analogue...

Computational modeling is an important aspect of the research on nuclear waste materials. In particular, atomistic simulations, when used complementary to experimental efforts, contribute to the scientific basis of safety case for nuclear waste repositories. Here we discuss the state-of-the-art and perspectives of atomistic modeling for nuclear was...

The extent and nature of covalency in actinide complexes is an important and complex question. There are two main mechanism of covalency, namely overlap of orbitals or degeneracy of the energies of the ligand and actinide metal, and computational approaches can play a significant part in rationalising the relative importance of each. In this work w...

The synthesis of two types of phosphine ligands that feature perfluorinated ponytails is reported. A bidentate (RfCH2CH2)2PCH2CH2P(CH2CH2Rf)2 (Rf = CF3(CF2) n ; n = 5, 7) and an alkoxyphosphine made by ring opening a fluorous epoxide, RfCH2CH(OH)CH2PR2 (Rf = CF3(CF2)7), have been prepared and spectroscopically characterised. The electronic effects...

Studtite, [UO2(η2-O2)(H2O)2].2H2O and metastudtite [UO2(η2-O2)(H2O)2] are important phase alteration of UO2 in a spent nuclear fuel repository and has previously been shown to react with Np(V). In this work we extend the study to Am(V) on a tracer scale and show spectroscopic evidence that the Am is incorporated into the structure of studtite as Am...

Oxidation of Cs 4 [U(NCS) 8 ] in MeCN or DMF affords structurally characterised examples of the mixed-valent UIV/VI compound Cs 14 [{U(NCS) 8 } 3 {UO 2 (NCS) 4 (H 2 O)]·4.5H 2 O, or the [UIV-UV-UIV][UVI] species [U(DMF) 8 (μ-O)U(NCS) 5 (μ-O)U(DMF) 7 (NCS)][UO 2 (NCS) 5 ]. Vibrational and magnetism data support their oxidation state...

The solid state structure of an N-heterocyclic borane 1,1,3,3-tetramethyl-1,3λ⁴,2-diazaborolidin-1-ium chloride is reported. This molecule features numerous Cl⋯H hydrogen bonds. Graphical Abstract The crystal structure of 1,1,3,3-tetramethyl-1,3λ⁴,2-diazaborolidin-1-ium chloride shows multiple C–H⋯Cl interactions in the solid state.

The benzimidazole derivative (E)-2-((4-(1H-benzo[d]imidazol-2-yl)phenylimino)methyl)-4-bromo phenol and the corresponding Zn(II), Ni(II), Cu(II), and Pd(II) complexes were prepared. The synthesized ligand and complexes were fully characterized and the ligand structure confirmed by single crystal X-ray diffraction analysis. The ability of this compo...

We report a set of theoretical calculations designed to examine the potential of model uranyl complexes to participate in hydrogen- and halogen-bonding. Potential energy scans for the interaction of [UO2Cl2(H2O)3] and [UO2(NCSe)2(H2O)3] with water demonstrate that uranyl is a weak hydrogen bond acceptor, but that equatorially coordinated water is a...

A series of uranyl thiocyanate and selenocyanate of the type [R4N]3[UO2(NCS)5] (R4=nBu4, Me3Bz, Et3Bz), [Ph4P][UO2(NCS)3(NO3)] and [R4N]3[UO2(NCSe)5] (R4= Me4,nPr4, Et3Bz) have been prepared and structurally characterized. The resulting noncovalent interactions have been examined and compared to other examples in the literature. The nature of these...

The minerals studtite, [UO2(η2-O2)(H2O)2]·2H2O, and metastudtite, [UO2(η2-O2)(H2O)2], are uranyl peroxide minerals that are major oxidative alteration phases of UO2 under conditions of geological storage. The dehydration of studtite has been studied using X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy. XPS of the U 4f regi...

The correlation between the structure of a series of uranyl minerals of the type [(UO2)8O2(OH)12] and M[(UO2)xOy(OH)z] (M = Na, x = 4, y = 2, z = 5; M = K2, x = 6, y = 4, z = 6; M = Ca, x = 6, y = 4, z = 6), and their electrochemical properties has been investigated using solid state cyclic voltammetry. Solid state electrochemical investigations at...

A series of complexes [Et4N][Ln(NCS)4(H2O)4] (Ln = Pr, Tb, Dy, Ho, Yb) have been structurally characterized, all showing the same structure, namely a distorted square antiprismatic coordination geometry, and the Ln-O and Ln-N bond lengths following the expected lanthanide contraction. When the counterion is Cs(+), a different structural motif is ob...

Perfluorooctanoic acid (PFOA) is a persistent organic pollutant and widespread in the environment. Three hosts have been synthesized based upon the formation of a fluorous cavity and hydrogen bonding receptors with the aim of extracting PFOA from water into organic solvents. The hosts based upon a calix[4]arene functionalized at the lower rim with...

A series of 10-((4-halo-2,6-diisopropylphenyl)imino)phenanthren-9-ones and derivatives of the phenanthrene-9,10-dione ligand have been synthesised and structurally characterised to explore two types of non-covalent interactions, namely the influence of the steric bulk upon the resulting C—H...pi and pi-stacking interactions and halogen bonding. Sel...

The solid state structure of 1,1,1,2,2,3,3-heptachloropropane is reported. This molecule features numerous type I and type II Cl⋯Cl interactions in the solid state as well as Cl⋯H hydrogen bonds. A Hirshfeld surface analysis is also presented.

A series of R2Sn (R = Me, Ph) complexes of the Schiff’s base salicylaldehyde acyldihydrazone with a methylene spacer of variable length have been structurally characterized in order to explore the prevalence of Sn…O non-covalent interactions. Structural studies show that these can exist, with the shortest Sn…O distance of 3.480(2) Å in this library...

The whole mol­ecule of the title compound, C14H20N4, is generated by inversion symmetry. The mid-point of the N=N bond is situated on the inversion centre. The conformation about this central N=N bond is E. The carbo­nitrile groups occupy axial positions on the cyclo­hexane rings. In the crystal, there are no significant inter­molecular inter­actio...

The crystal structure of [Ph4P][NCS]·HNCS is reported. This is the first structural determination of isothiocyanic acid and hydrogen bonding between the NCS anion and HNCS fragment explored using computational chemistry.

The use of laser sources can expand the range of applications of photochemical surface functionalization strategies, increasing reaction rate and sample throughput. However, high irradiances can result in thermal effects and/or changes in the mechanism of photoinduced reactions. In this work we report on the use of a pulsed UV laser source for the...

Abstract The magnetic and optical properties of Rare Earths (REs) make these elements indispensable in green technology such as wind turbines and hybrid electric vehicles. Bastnesite, Monazite and Xenotime are the most common RE minerals. Various methods exist for extraction/separation of RE from their minerals. In general, the RE is concentrated b...

The reaction of a number of uranyl minerals of the (oxy)hydroxide, phosphate and carbonate types with Eu(III), as a surrogate for Am(III), have been investigated. A photoluminescence study shows that Eu(III) can interact with the uranyl minerals Ca[(UO2)6(O)4(OH)6]·8H2O (becquerelite) and A[UO2(CO3)3]·xH2O (A/x = K3Na/1, grimselite; CaNa2/6, anders...

The first example of a uranyl selenocyanate compound is reported. The compound [Et4N]3[UO2(NCSe)5] has been synthesized and fully characterized by vibrational and multinuclear (¹H, ¹³C{¹H} and ⁷⁷Se{¹H}) NMR spectroscopy. The photophysical properties have also been recorded and trends in a series of uranyl pseudohalides discussed. Spectroscopic evid...

Synergistic extraction method has been developed for the extraction of Eu(III) from buffer solution of pH 3 using 1 M synergic mixture of di-n-butylsulfoxide (DBSO) and Cyanex-272 in chloroform. The extracted europium was measured spectrophotometrically by using 0.01 % solution of arsenazo(III) in 3 M perchloric acid as chromogenic reagent. Various...

The solid state structures of CF3(CF2)5CH2CO2H and a fluorous triazole are reported, both of which display a wide variety and large number of non-covalent interactions in their packing . The solid state structure of CF3(CF2)5CH2CO2H is stabilized by multiple F…F contacts but only one C—H…F—C interaction, as well as O—H…O and C—H…O hydrogen bonds. I...

At the beginning of this century, the European Union engaged in a discussion on the necessity to shift to softer modes of governance, less detrimental for state sovereignty, which prompted lively academic debates. But how much has actually changed in the day-to-day practice has not been systematically analysed, and the severe economic and financial...

The amino acid [1-(aminomethyl)cyclohexyl]acetic acid was reacted with 2-hydroxynaphthaldehyde to produce the Schiff base ligand [1-({[(Z)-(2-hydroxynaphthalen-1-yl)methylidene]amino}methyl)cyclohexyl]acetic acid (H-HMAC) which was fully characterized spectroscopically and by single crystal diffraction. It was reacted with metal ions to produce com...

A comprehensive study of the complexes A4[U(NCS)8] (A = Cs, Et4N, nBu4N) and A3[UO2(NCS)5] (A = Cs, Et4N) is described, with the crystal structures of [nBu4N]4[U(NCS)8]·2MeCN and Cs3[UO2(NCS)5]·O0.5 reported. The magnetic properties of square antiprismatic Cs4[U(NCS)8] and cubic [Et4N]4[U(NCS)8] have been probed by SQUID magnetometry. The geometry...

The solid-sate structures of the two uranyl peroxides studtite, [UO2(η(2)-O2)(H2O)2]·2H2O, and metastudtite [UO2(η(2)-O2)(H2O)2] have been determined by U-L3 edge extended X-ray absorption fine structure (EXAFS) spectroscopy and show that upon removal of the interstitial water in studtite there are structural changes with a small shortening of the...

The synthesis of a series of uranyl compounds via oxidation of [Li(THF)4][UX5(THF)] (X = Cl, Br, I) in the presence of Ph3P[double bond, length as m-dash]O is described. The solid state structures of [Li(O[double bond, length as m-dash]PPh3)(MeCN)2]2[UO2Cl4], [UO2Br2(O[double bond, length as m-dash]PPh3)2] and [Li(O[double bond, length as m-dash]PP...

The storage of spent nuclear fuels for long periods of time in geological repositories is one proposed solution to the stewardship of legacy, current and future nuclear waste. Recent studies have shown that UO2, the major component of spent nuclear fuel, can oxidise under repository conditions to a number of secondary phases. The weathering of natu...

The solid-state structure of the known complex [Et4N][U(NCS)5(bipy)2] has been re-determined and a detailed spectroscopic and magnetic study has been performed in order to confirm the oxidation states of both metal and bipy ligand. Electronic absorption and infrared spectroscopy suggest that the uranium is in its +4 oxidation state and this has bee...

The uranyl aryloxide [UO2(OAr)2(THF)2] (Ar = 2,6-(t)Bu2-C6H2) is an active catalyst for the ring-opening cyclo-oligomerization of ε-caprolactone and δ-valerolactone but not for β-butyrolactone, γ-butyrolactone, and rac-lactide. (1)H EXSY measurements give the thermodynamic parameters for exchange of monomer and coordinated THF, and rates of polymer...

Enormous interest had been paid to the coordination chemistry of alkali and alkaline metal ions because of their role inside body viz; their Li+/Na+ exchange inside the cell lead to different diseases like neuropathy, hypertension, microalbuminuria, cardiac and vascular hypertrophy, obesity, and insulin resistance. It has been presumed that alkali...

The Schiff base 2-[(E)-(quinolin-3-ylimino)methyl]phenol (H-QMP) was crystalized in Pc space group and complexed with Ni (II) and Co (II) in [M(QMP)2] and Cu (II) and Zn (II) in [M(QMP)(CH3COO)]H2O compositions. Elemental analyses, mass spectrometry, IR, UV-visible spectroscopy, conductance study and magnetic susceptibilities were used to character...

Background Coumarin and its derivatives are biologically very active. It was found that the enhanced activities are dependent on the coumarin nucleus. Biological significance of these compounds include anti-bacterial, anti-thrombotic and vasodilatory, anti-mutagenic, lipoxygenase and cyclooxygenase inhibition, scavenging of reactive oxygen species,...

Emission spectroscopy has been used for the first time in a spectroscopic study of a family of uranium(IV) halide complexes in non-aqueous media. The room temperature electronic absorption spectra of the simple coordination compounds [Li(THF)4][UX5(THF)] (X = Cl, Br, I), [Et4N]2[UCl6] and UCl4 in THF have been recorded and all transitions assigned...

Transition metal [Co, Ni, Cu and Zn(II) acetates] complexes of salicylaldehyde derived Schiff bases, 2-{(E)-[(4-chlorophenyl)imino]methyl}phenol (CIMP) and 2-{(E)-[(4-bromophenyl)imino]methyl}phenol (BIMP) were synthesized and characterized by various anal. and spectroscopic studies. The Schiff base ligands and their metal complexes were also scree...

The chemistry of the uranyl ion ([UO2]2+) has evolved remarkably over the past few years, with unexpected reactivity observed that challenge our understanding of this ion, and of actinides in general. This review highlights some recent advances in the field, focussing on the organometallic chemistry of the uranyl moiety, which is not well developed...

The coordination and organometallic chemistry of U(III) has been revolutionised by the preparation of the key starting materials [UI3(solv)(4)] (solv = THF, py, 1/2DME), [U{N(SiMe3)(2)}(3)] and [U(OTf)(3)] and fascinating transformations have resulted. Herein the chemistry of these compounds is reviewed focussing on the initial reactivity of these...

The title compound, a phase alteration product of spent nuclear fuel, is characterized by solid state cyclic voltammetry and Raman spectroscopy.

A comprehensive computational study on the ring-opening polymerization of propylene oxide catalyzed by uranyl chloride [UO(2)Cl(2)(THF)(3)] and the uranyl aryloxide [UO(2)(OAr)(2)(THF)(2)] (Ar = 2,6-(t)Bu(2)C(6)H(3)) is reported. The initiation and propagation steps have been probed and significant differences between the two catalysts discovered....

The unusual uranyl peroxide studtite, [UO(2)(η(2)-O(2))(H(2)O)(2)]·2H(2)O, is a phase alteration product of spent nuclear fuel and has been characterized by solid-state cyclic voltammetry. The voltammogram exhibits two reduction waves that have been assigned to the U(VI/V) redox couple at -0.74 V and to the U(V/IV) redox couple at -1.10 V. This pot...

2-[(E)-(Quinolin-3-ylimino)methyl]phenol (H-QMP) was synthesized by condensing salicylaldehyde with 2-aminoquinoline and fully characterized by mass spectrometry, 1H and 13C{1H} NMR, and IR spectroscopies. The metal complexes [M(QMP)(OAc)]H2O where M = Cu(II) and Zn(II) and [M(QMP)2] where M = Ni and Co(II) were prepd. from the metal acetates. All...

The synthesis of highly fluorinated zinc carboxylates [{CF3(CF2)5CH2CH2CO2}2Zn], and alkoxides [{CF3(CF2)5CH2CH2O}2Zn(OEt2)2] and their use as catalysts for the ring opening polymerisation of ecaprolactone are described. Quenching the polymerisation reaction with fluorous acids or alcohols regenerates the catalyst, which can be recovered by fluorou...

The uranyl aryloxide, [UO(2)(OAr)(2)(THF)(2)], and uranyl chloride, [UO(2)Cl(2)(THF)(3)] or [UO(2)Cl(2)(THF)(2)](2) act as pre-catalysts for the ring opening polymerization of propylene oxide and cyclohexene oxide. Coordination of the monomers has been investigated using (1)H EXSY spectroscopy and kinetic and thermodynamic parameters reported. NMR...

The solid state structures of three compounds that contain a perfluorinated chain, CF(3)(CF(2))(5)CH(2)CH(CH(3))CO(2)H, CF(3)(CF(2))(5)(CH(2))(4)(CF(2))(5)CF(3) and {CF(3)(CF(2))(5)CH(2)CH(2)}(3)P═O have been compared and a number of C-F···F-C and C-F···H-C interactions that are closer than the sum of the van der Waals radii have been identified. T...

New highly fluorinated monodentate and bidentate phosphine oxide compds. of the type {CF3(CF2)nCH2CH2}3P=O (n = 5, 9) and [{CF3(CF2)5CH2CH2}2P(O)CH2CH2P(O){CH2CH2(CF2)5CF3}] have been prepd. Their ability to ext. a no. of metals and radionuclides from aq. solns. into perfluorinated solvents has been established and the extractable species investiga...

A series of highly fluorinated compounds of the type {CF3(CF2)5CH2CH2}3P=O, [{CF3(CF2)5CH2CH2}2P(E)CH2CH2P(E){CH2CH2(CF2)5CF3}] and {CF3(CF2)5CH2CH2}2C=E (E = O or S) have been examined for their ability to extract gold(III) from aqueous solutions. The phosphine oxides have been studied under liquid–liquid extraction conditions from water into perf...

The extraction efficiency of some perfluorinated phenols for the removal of Cs+ and Sr2+ from aqueous solutions is reported. The perfluorinated phenols C6F5OH and 2,3,5,6-C6F4HOH have been shown to extract Sr-90(2+) or Cs+ from aqueous solutions into a 100: 1 mixture of toluene and pyridine in reasonable efficiencies, using radio-tracer and ICP-OES...

The reactions of secondary phosphines with radical sources have been investigated. A stoichiometric dehydrocoupling of Ph2PH with 1,1'-azobis[cyclohexane-1-carbonitrile] (VAZO 88) affords tetraphenyldiphosphine in good yields, while redn. of the nitrosyl function was obsd. upon using 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO). Dialkylphosphine-bor...

The prepn. of a ketone, F3C(CF2)5(CH2)2CO(CH2)2(CF2)5CF3, with two long chain perfluoroalkyl groups is reported via the coupling reaction of a perfluorinated alkylzinc reagent and a perfluoro-acid chloride. Using its unique thermomorphic properties, this ketone has been investigated in the heterogeneous removal of heavy metals M2+ (M = Sn, Cd, Pb,...

A coupling reaction between pyridine and dichloromethane has been obsd. in the presence of uranyl chloride and a base. The x-ray structure of the complex bis[1,1'-methylenebis(pyridinium)]dichlorodetetrachlorodioxouranate(IV) is reported and consists of a no. of H···Cl and π-π interactions to form an open mussel solid-state structure. [on SciFinder...

Attempts have been made to prepare a variety of groups 13–15 N-heterocyclic carbenoid systems. The work in group 13 led to two structurally characterized, paramagnetic gallium(III) heterocycles, [I2Ga{[N(R)C(Me)]2}], R=C6H3Pr2i-2,6(Ar) or C6H3(C6H4But-4)2-2,6. Reduction of the former gave the anionic gallium(I) heterocyclic complex, [K(tmeda)][:Ga{...

The reaction of [(η7-C7H7)Zr(η5-C5H5)] with two Lewis bases, tetramethylimidazolin-2-ylidene and PMe3, is reported and their stability probed via spectroscopic and theor. methods. The strongly σ-basic N-heterocyclic carbene forms a stable adduct which has been structurally characterized, while the PMe3 ligand coordinates weakly to the metal center....

The reactivity of several transition metal half sandwich complexes towards an anionic gallium(I) heterocyclic complex, [K(tmeda)][Ga{[N(Ar)C(H)]2}] (Ar = C6H3Pri2-2,6), has been investigated. This has led to the anionic half sandwich complexes, [K(tmeda)][(C5H4R)M(CO)n[Ga{[N(Ar)C(H)]2}]] (M = V, R = H, n = 3; M = Mn, R = Me, n = 2; M = Co, R = H, n...

The reactivity of a series of Ga(I), Ga(II) and Ga(III) heterocyclic compounds towards a number of Group 15 substrates has been investigated with a view to prepare examples of gallium-terminal pnictinidene complexes. Although no examples of such complexes were isolated, a number of novel complexes have been prepared. The reactions of the gallium(I)...

The synthesis and characterization of the amidines, (tript)C(NR)(NHR), R = Pri or cyclohexyl (Cy), tript = triptycenyl, and Li amidinate complexes, [Li(THF)2{(tript)C(NR)2}] bearing the bulky triptycenyl substituent on the amidine or amidinate backbone C is described. NMR spectroscopic studies showed these to exist solely as their Z-syn isomeric fo...

This article summarizes the synthetic strategies that have been used to prepare anionic five-membered and neutral six-membered heterocycles containing a group 13 metal in the +1 oxidation state. In addition, a survey of the coordination chemistry and reactivity of these species is described, drawing comparisons with the well known N-heterocyclic ca...

The reactivity of an anionic gallium(I) heterocycle, [K(tmeda)][:Ga([N(Ar)C(H)]2)], Ar = C6H3Pr(i)2-2,6, towards sources of elemental chalcogens and diorgano-dichalcogenides has been investigated and comparisons drawn with the reactivity of the valence isoelectronic N-heterocyclic carbene class of ligand. The reactions of the heterocycle with N2O o...

Paramagnetic diazabutadienegallium(II or III) complexes, [(Ar-DAB)2Ga] and [{(Ar-DAB*)GaX}2] (X = Br or I; Ar-DAB = {N(Ar)C(H)}2, Ar = 2,6-diisopropylphenyl), have been prepared by reactions of an anionic gallium N-heterocyclic carbene analogue, [K(tmeda)][:Ga(Ar-DAB)], with either "GaI" or [MoBr2(CO)2(PPh3)2]. A related InIII complex, [(Ar-DAB*)In...

The current renaissance in main group chemistry has been fuelled by the remarkable array of fundamentally interesting yet synthetically applicable low oxidation state p-block compounds that have appeared over the last decade. Their syntheses generally require the ready availability of low oxidation state element halide precursors. In the case of ga...

The reactions of the paramagnetic gallium(II) complex [{(Bu(t)-DAB)GaI}2] (Bu(t)-DAB = {(Bu(t))NC(H)}2) with the alkali metal pnictides [ME(SiMe3)2] (M = Li or Na; E = N, P, or As) have been carried out under a range of stoichiometries. The 1:2 reactions have led to a series of paramagnetic gallium(III)-pnictide complexes, [(Bu(t)-DAB)Ga{E(SiMe3)2}...

Treatment of "ZrCp2" with the digallane(4), [{Ga[N(Ar)C(H)]2}2], Ar = C6H3Pri2-2,6, in the presence of excess Bu(n)Li leads to the first example of a gallyl-Group 4 complex, [Cp2Zr{Ga[N(Ar)C(H)]2}2][Li(THF)4], via an unprecedented oxidative insertion reaction; the paramagnetic complex has been characterised by X-ray crystallography and EPR spectros...

Reaction of triptycenyl lithium with elemental Te in PhMe (3h reflux) gave 10% title compd., the crystal structure of which was detd. [on SciFinder(R)]

The reaction of a gallium(II)-phosphine complex, [Ga 2I 4{P(H)Cy 2} 2], Cy = cyclohexyl, with Et 3N gives rise to the first gallium(II)-dialkylphosphide complex, [Et 3NH] 2[Ga 4I 8(PCy 2) 2], which contains an unprecedented Ga 4P 2 heterocycle. The reaction of a dialkyl phosphine-gallium(II) iodide complex, [Ga 2I 4{P(H)Cy 2} 2], Cy = cyclohexyl, w...

An unprecedented π-cyclopentadienyl-bridged digallane complex, [{Ga[N(Ar)C(H)]2}2{μ-CpK(tmeda)2}] (Ar = C6H3Pri2-2,6), incorporating the first structurally characterized π-interaction with a Ga(II) center, results from the oxidative coupling of an anionic gallium(I) heterocycle with cyclopentadienylthallium(I). This compound can be regarded as an i...

High thermal stability is a characteristic feature of the depicted amido indium hydride complex (In red; hydride yellow), which is amongst the first to be synthesized and characterized. The stability arises from steric shielding of the In-H bond, which frustrates the formation of the intermolecular In-H-In bridges.

The reactions of 9-lithiotriptycene with AlCl3, GaCl3 and InBr3 yielded the complexes, [(tript)AlCl2(OEt2)], [(tript)GaCl2(THF)] and [(tript)InBr(μ-Br)2Li(OEt2)2], tript = 9-triptycenyl, resp. The latter two complexes were structurally characterized by single crystal x-ray anal. The corresponding reactions of 9-lithiotriptycene with ECl3 (E = P, As...

GaI reacts with 2,2'-bipyridine (bipy) to give [Ga(bipy)3][I]3, [{(bipy)2Ga}2(μ-OH)2]2[Ga2I6][I]6 or [{(bipy)2Ga}2(μ-OH)2][I]4, depending upon the reaction conditions. GaI also reacts with 4'-phenyl-2,2':6',2''-terpyridine (Phterpy) to give [GaI2(Phterpy)][I]. When GaI is treated with the imino-substituted pyridines RN:C(H)Py, Py = 2-pyridyl, R = A...

The 1st Fe complex of an anionic Ga N-heterocyclic carbene analog, [Fe(CO)4{Ga[N(Ar)C(H)]2}]- Ar = C6H3Pri2-2,6, was prepd. and shown to have an unusual polymeric structure in the solid state. Theoretical studies have pointed towards minimal Fe → Ga back-bonding in this complex. [on SciFinder(R)]

Tetra-tert-butyl­tetraphosphacubane, P4C4tBu4, reacts with water in the presence of ‘GaI’ to yield two products, namely 4,6,7,8-tetra-tert-butyl-1,2,3-triphospha-5-phospho­niatetra­cyclo­[3.2.1.02,4.03,8]­oct-6-ene tetra­iodo­gallate(III), (C20H37P4)[GaI4], and tri­iodo(3,5,7,8-tetra-tert-butyl-1,2,4λ⁵,6-tetra­phos­pha­tetra­cyclo­[4.1.1.02,5.07,8]...

CAPLUS AN 2004:256032(Journal)

The structure of the N-heterocyclic gallium hydride complex, [GaH2I{CN(Mes)C2H2N(Mes)}], Mes = mesityl, shows both hydride ligands to be bonded to the distorted tetrahedral gallium centre. Copyright © 2003 John Wiley & Sons, Ltd.

The synthesis, spectroscopic and structural characterization of the novel nickel-gallium(I) heterocycle complex, [{Ga[N(Ar)C(H)]2}2Ni(mu-Cp)K(tmeda)(mu-Cp)K(mu-C7H8)0.5]infinity, Ar = C6H3Pri2-2,6, are reported. The compound is polymeric in the solid state and reacts with an N-heterocyclic carbene to give the neutral, square planar complex, trans-[...

The reactions of a variety of primary and secondary amines and secondary phosphanes with “GaI” have been examined. In all cases disproportionation reactions occurred which led to the gallium(II) iodide complexes [Ga2I4(L)2] [L = NCyH2, NtBuH2, NCy2H, PCy2H or PtBu2H (Cy = cyclohexyl)]. All complexes have been crystallographically characterised and...

The first covalently bonded metal complexes derived from an anionic gallium carbene analogue (see picture) show remarkable thermal stability in the solid state. This fact suggests that gallium(1) heterocycles should prove to be versatile ligands towards both main-group and transition-metal fragments.

The reactivity of the carbene stabilized indium trihydride complex, [InH3(IMes)] IMes = 1,3-dimesitylimidazol-2-ylidene, toward a variety of transition metal complexes has been investigated. The study has shown that the InH3 complex can act as a carbene and/or hydride transfer reagent to transition metal centers but does not yield heterobimetallic...

The title compound, C14H24N⁺·I⁻, was formed by a Schiff base condensation of 2,6-diiso­propyl­aniline and acetone, using GaI as a Lewis acid. A strong interaction from the iminium hydrogen N—H to the iodide counter-ion is observed. The ¹H and ¹³C NMR data are also reported.

The triphosphorus macrocycle 1,5,9-triethyl-1,5,9-triphosphacyclododecane, 12[ane]P3Et3, reacts with [V(CO)6]− under photolytic conditions to produce fac-[(12[ane]P3Et3)V(CO)3]− (1) which has been isolated as its Et4N salt. This can be oxidised to the neutral 17 electron complex fac-(12[ane]P3Et3)V(CO)3 (2), which has been characterised by EPR spec...

Treatment of 'GaI' with a 1,3-diyne, Me3SiC[triple bond]CC[triple bond]CSiMe3, leads to C-C coupling reactions and the isolation of the novel organogallium species, [Ga4I8[C8(SiMe3)4]], as two isomeric forms; their X-ray crystal structures show them to contain the first structurally authenticated gem-organodigallium fragments and to exhibit rare ex...

The synthesis of Re(III), Re(I) and Mn(I) compounds of the macrocyclic phosphine ligand 1,5,9-trialkyl-1,5,9-triphosphacyclododecane, 12[ane]P3R3 (R = Et, iBu) is described. The reaction of 12[ane]P3R3 with ReCl3(PPh3)2(CH3CN) or ReCl3(PPhMe2)3 gives rise to the octahedral d4 complexes (12[ane]P3R3)ReCl3 (1R). Reduction of 1iBu with Na/Hg under a C...

The reactions of two diazabutadiene ligands, Ar-DAB [(ArN:CH)2, Ar = 2,6-Pri2C6H3] and But-DAB [(ButN:CH)2] with either GaI or an AlI3/Al mixt. have afforded the paramagnetic compds., [{IGaII(But-DAB)}2], [I2GaIII(But-DAB)] and [I2AlIII(Ar-DAB)] which were characterized by x-ray crystallog. and EPR spectroscopy. The diamagnetic, ionic complex, [I2A...

The syntheses of two Group 13 complexes of the sterically demanding carbene, 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, (IPr), are reported, vis. [MX3(IPr)] M=Al, X=H; M=In, X=Br; both of which have been structurally characterised. Also reported is the crystal structure of the imidazolium salt [IPrH][InBr4], formed by the presence of adventi...

Some early transition metal (Ti, V, Cr) complexes of the triphosphorus macrocycle 1,5,9-triethyl-1,5,9-triphosphacyclododecane, [12]aneP3Et3, and related derivs. [12]aneP3R3 (R = Ph, C3H6OMe) were evaluated as catalysts in polymn. of ethene and propene. All complexes of the type [12]aneP3Et3MCl3 display moderate catalytic activity in the homogeneou...

The reactions of 1,5,9-triethyl-1,5,9-triphosphacyclododecane, [12]aneP3Et3, with first-row transition metal halides MCl3 [M = Ti (1), V (2), and Cr (3)] or their THF adducts are reported. The oxidation of 2 gives the complex ([12]aneP3Et3)V(O)Cl2 (4). This is the first example of a phosphane ligand that is trans to a vanadyl moiety. Also reported...