A5035645976- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Organometallic Complex Synthesis and Catalysis
- Synthesis and characterization of novel inorganic/organometallic compounds
- Coordination Chemistry and Organometallics
- Crystallography and molecular interactions
- Organoboron and organosilicon chemistry
- Synthetic Organic Chemistry Methods
- Metal complexes synthesis and properties
- Asymmetric Hydrogenation and Catalysis
- Carbon dioxide utilization in catalysis
- Chemical Synthesis and Analysis
- Inorganic Chemistry and Materials
- Radioactive element chemistry and processing
- Magnetism in coordination complexes
- Ferrocene Chemistry and Applications
- Catalytic Cross-Coupling Reactions
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Supramolecular Chemistry and Complexes
- Organophosphorus compounds synthesis
- Polyoxometalates: Synthesis and Applications
- Lanthanide and Transition Metal Complexes
- Catalysis and Oxidation Reactions
- Chemical Reaction Mechanisms
- Synthesis and Reactivity of Heterocycles
Victoria University of Wellington
2016-2025
University of Sussex
2008-2017
Victoria University
2012-2016
Brighton Hospital
2015
Manisa Celal Bayar University
2007-2009
University of Bath
2009
Rudjer Boskovic Institute
2009
University of Tartu
2009
Lawrence Berkeley National Laboratory
1999-2005
University of California, Berkeley
1999-2005
The aim of this perspective is to highlight the continued development and application amidines guanidines as neutral, N-based donor ligands in coordination chemistry. From a sporadic interest dating back 1980s, work on these two closely related classes compounds has steadily grown, with examples evermore sophisticated substitution about common ligand framework being developed address specific problems number fields These have shown varied modes at metals from across periodic table, their...
Bicyclic guanidines have physical, electronic and chemical properties that differentiate them from their acyclic counterparts, with many of these characteristics directly imposed by the rigid framework. These distinctive features led to this class molecule finding practical applications in areas chemistry, including organocatalysis as ligands coordination compounds. In addition neutral molecules, corresponding cationic (guanidinium) anionic (guanidinate) species also been widely studied....
Abstract A seven‐membered N , ′‐heterocyclic potassium alumanyl nucleophile is introduced and utilised in the metathetical synthesis of Mg−Al Ca−Al bonded derivatives. Both species have been characterised by experimental theoretical means, allowing a rationalisation greater reactivity heavier group 2 implied an initial assay their reactivity.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTCationic Aluminum Alkyl Complexes Incorporating Amidinate Ligands. Transition-Metal-Free Ethylene Polymerization CatalystsMartyn P. Coles and Richard F. JordanView Author Information Department of Chemistry, The University Iowa City, 52242 Cite this: J. Am. Chem. Soc. 1997, 119, 34, 8125–8126Publication Date (Web):August 27, 1997Publication History Received3 June 1997Published online27 August inissue 1...
The synthesis and structures of mono- bis(amidinate) aluminum complexes are described. reaction AlMe3 1 equiv carbodiimide, R'NCNR', affords {MeC(NR')2}AlMe2 (1a, R' = iPr; 1b, Cy cyclohexyl). R'NCNR' with MeLi or tBuLi generates Li[RC(NR')2] (2a, R Me, 3a, tBu, 3b, Cy; 3c, SiMe3). 2a, 3b may be isolated reacted in situ, while attempted isolation 3c gave [Li(tBuCN){μ-N(SiMe3)2}]2 (3d). AlCl3 2a 3a−c {RC(NR')2}AlCl2 (4a, Me; 5a−c, tBu), the AlMe2Cl {tBuC(NR')2}AlMe2 (6a−c). Alkylation 5a,b 2...
Aluminum and gallium amidinate complexes, {RC(NR')2}MMe2 (R, R' = alkyl; M Al, Ga), react with the "cationic activators" [Ph3C][B(C6F5)4] B(C6F5)3 to yield cationic Al Ga alkyl species whose structures are strongly influenced by steric properties of ligand. The reaction acetamidinate complexes {MeC(NR')2}AlMe2 (R' iPr, 1a; Cy, 3a) 0.5 equiv or yields {MeC(NR')2}2Al2Me3+ 2a+; 4a+) as B(C6F5)4- MeB(C6F5)3- salts. X-ray crystallographic analyses establish that 2a+ 4a+ double-amidinate-bridged...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTReversible Ethylene Cycloaddition Reactions of Cationic Aluminum β-Diketiminate ComplexesCatherine E. Radzewich, Martyn P. Coles, and Richard F. JordanView Author Information Department Chemistry, The University Iowa City, 52242 Cite this: J. Am. Chem. Soc. 1998, 120, 36, 9384–9385Publication Date (Web):August 28, 1998Publication History Received27 May 1998Published online28 August inissue 1 September...
Abstract The potassium aluminyl complex K[Al(NON Ar )] (NON=NON =[O(SiMe 2 NAr) ] 2− , Ar=2,6‐ i Pr C 6 H 3 ) reacts with 1,3,5,7‐cyclooctatetraene (COT) to give )(COT)]. COT‐ligand is present in the asymmetric unit as a planar μ ‐η :η 8 ‐bridge between Al and K, additional K⋅⋅⋅π‐aryl interactions neighboring molecules that generate helical chain. DFT calculations indicate significant aromatic character, consistent reduction [COT] . Addition of 18‐crown‐6 causes rearrangement ‐carbocycle...
Abstract More than 80 years after Paneth’s report of dimethyl bismuth, the first monomeric Bi II radical that is stable in solid state has been isolated and characterized. Reduction diamidobismuth(III) chloride Bi(NON Ar )Cl (NON =[O(SiMe 2 NAr) ] 2− ; Ar=2,6‐ i Pr C 6 H 3 ) with magnesium affords . ). X‐ray crystallographic measurements are consistent a two‐coordinate bismuth +2 oxidation no short intermolecular contacts, solid‐state SQUID magnetic indicate paramagnetic compound single...
A seven-membered N,N'-heterocyclic potassium alumanyl nucleophile is introduced and utilised in the metathetical synthesis of Mg-Al Ca-Al bonded derivatives. Both species have been characterised by experimental theoretical means, allowing a rationalisation greater reactivity heavier group 2 implied an initial assay their reactivity.Al‐Ca‐Wrap: Die Reaktion eines siebengliedrigen cyclischen Alumanyl‐Anions mit einem β‐Diketiminato‐Calciumtetraphenylborat bietet einen leichten Zugang zu...
Expanding knowledge of low valent aluminium chemistry, rubidium and caesium aluminyls are reported to complete the group 1 (Li-Cs) set metal aluminyls. Both compounds crystallize as a contacted dimeric pair supported by M⋯π(arene) interactions with pronounced twist between aluminyl units. Density functional theory calculations show symmetrical bonding M Al atoms, an centred lone-pair donating into vacant Rb Cs orbitals. Interestingly, despite their structural similarity enables C-H bond...
Abstract The insertion reaction between 1 equiv. of carbodiimide, R′N=C=NR′, and the zinc bis(amide) [Zn{N(SiMe 3 ) 2 } ] affords homoleptic zinc( II guanidinate compounds [Zn{(Me Si) NC(NR′) ( , R′ = i Pr; 4 Cy) in preference to monosubstituted compounds. Compound also results from protonation neutral guanidine (Me NC(N Pr)(NH Pr) with or ZnMe . In contrast, N ‐dimethylguanidine analogue Me reacts cleanly afford dimeric species [Zn{Me }Me] 5 ). Attempted Zn−C bond 2,6‐di‐ tert ‐butylphenol...
Bismuth diphenylphosphanides Bi(NONR )(PPh2 ) (NONR =[O(SiMe2 NR)2 ], R=tBu, 2,6-iPr2 C6 H3 , Aryl) undergo facile decomposition via single-electron processes to form reduced Bi and P species. The corresponding derivatives )(PCy2 are stable. Reaction of the isolated BiII radical . Bi(NONAr with white phosphorus (P4 proceeds reversible selective activation a single P-P bond afford bimetallic μ,η1:1 -bicyclo[1.1.0]tetraphosphabutane compound.
The reaction of the potassium aluminyl K[Al(NONDipp)] (NONDipp = [O(SiMe2NDipp)2]2-, Dipp 2,6-iPr2C6H3) with an organic azide generates aluminium imide complex, K[Al(NONDipp)(NMes)] (Mes mesityl 2,4,6-Me3C6H2). DFT calculations indicate Al-Nimide interaction is polarized but has appreciable multiple-bond character. This demonstrated experimentally by carbon dioxide, giving a rare example main group carbamate dianion via [2+2] cycloaddition reaction.
Bismuth(iii) TEMPOxide compounds have been synthesized from the coupling of Bi(ii) species with TEMPO˙ radical. The steric profile supporting bis(amido)disiloxane ligand promotes different fluxional behaviour in solution, and DFT calculations suggest variation Bi-O bond character. These are active catalysts for oxidative TEMPO silane substrates, believed to proceed via metathesis Si-H bonds followed by decomposition bismuth-hydride intermediate species.
We report the anion [Al(NONAr )(Se)]- (NONAr =[O(SiMe2 NAr)2 ]2- , Ar=2,6-iPr2 C6 H3 ), which is an isoelectronic Group 13 metal analogue of carbonyl group containing aluminium-selenium multiple bond. It was synthesized in a single step from reaction aluminyl )]- with elemental selenium. Spectroscopic, crystallographic, and computational analysis confirmed bonding between aluminium Addition second equivalent selenium afforded diselenirane, )(κ2 -Se2 dioxirane group.
Abstract To date, aluminyl anions have been exclusively isolated as their potassium salts. We report herein the synthesis of lithium and sodium aluminyls, M 2 [Al(NON Dipp )] ( =Li, Na. NON =[O(SiMe NDipp) ] 2− ; Dipp=2,6‐ i Pr C 6 H 3 ). Both compounds crystallize from non‐coordinating solvent “slipped” contacted dimeric pairs with strong ⋅⋅⋅π(aryl) interactions. Isolation Et O solution affords monomeric ion (NON )Al‐ (Et O) , which contain discrete Al−Li Al−Na bonds. The ability full...
The tris(tert-butoxy)siloxy complex Ti[OSi(OtBu)3]4 (1) was pyrolytically converted at low temperatures to the theoretical yield of homogeneous TiO2·4SiO2 materials. 1 also serves as a soluble model for isolated, tetrahedral titanium atoms in silica matrix. solid-state transformation affords low-surface-area material (2a, 22 m2 g-1 samples heated 500 °C) consisting roughly spherical particles with an average diameter ca. 25 nm (by transmission electron microscopy). solution-phase thermolysis...
The synthesis and structures of new aluminum complexes incorporating guanidinate ligands (R2NC(NR')2-) are described. reaction iPrNCNiPr with LiNR2 reagents yields Li[R2NC(NiPr)2] salts, which reacted in situ AlCl3 or AlMe2Cl to afford {R2NC(NiPr)2}AlCl2 (1a, R = Me; 1b, Et; 1c, iPr; 1d, SiMe3) {R2NC(NiPr)2}AlMe2 (2a, 2b, 2c, iPr), respectively. 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH) AlMe3 generates {(μ-hpp)AlMe2}2 (3). Complexes 1a, 3 have been characterized by X-ray...
The bis-guanidino compound H2C{hpp}2 (I; hppH = 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) has been converted to the monocation [I-H]+ and isolated as chloride tetraphenylborate salts. Solution-state spectroscopic data do not differentiate protonated guanidinium from neutral guanidino group but suggest intramolecular "—N—H···N═" hydrogen bonding form an eight-membered C3N4H heterocycle. Solid-state CPMAS 15N NMR spectroscopy confirms protonation at one of imine nitrogens, although...
Hydrogenation of CO: The reaction [U(η-C8H6{SiiPr3-1,4}2)(η-Cp*)] in toluene with CO and H2 at subambient to ambient temperature pressure affords the methoxide complex [U(η-C8H6{SiiPr3-1,4}2)(η-Cp*)OMe]. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted by authors. Please note: publisher is responsible for content functionality any supporting information supplied...
Complexes [Ce(NR2)3] (1) or [Ce(NR″2)3] (2) were cerium(III) precursors to the X-ray characterised crystalline oligomeric oxygen-containing amidocerium(IV) compounds [{Ce(NR2)2(μ-O)}n] (3, n = 2; 4, 3), [{Ce(NR″2)2(μ-O)}4] (5), [{(R2N)3Ce}2(μ-OMOM)] (6, M Na; 7, K), [{(R2N)3CeOCe(NR2)2}2(μ-OKOK)] (8), and [{Ce(NR2)3}2(μ-η2:η2-O2)]·2CnH2n+2 (9, 6; 9′, 5) [R SiMe3, NR″2 TMP NC(Me)2(CH2)3CMe2]. Each was isolated in low, for 5 very yield. Except oxidising agent O2 at −27 °C hexane 6, 8, 9),...
A series of low-coordinate tin and lead cationic complexes have been synthesized using the bulky β-diketiminate ligand [{N(2,6-iPr2C6H3)C(Me)}2CH]− (BDI) to stabilize metal center. Two different routes [(BDI)Sn]+[X]− [(BDI)Pb]+[X]− were explored (X = B(C6F5)4, AlCl4, MeB(C6F5)3): abstraction chloride with a Lewis acid from (BDI)SnCl (BDI)PbCl methyl group borane (BDI)SnMe (BDI)PbMe. The crystal structures cations determined; in both, solvent molecules found coordinate In case...