A5087369600- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Crystallography and molecular interactions
- Chemical Synthesis and Analysis
- Asymmetric Synthesis and Catalysis
- Organometallic Complex Synthesis and Catalysis
- Magnetism in coordination complexes
- Synthetic Organic Chemistry Methods
- Catalytic C–H Functionalization Methods
- Asymmetric Hydrogenation and Catalysis
- Organoboron and organosilicon chemistry
- Molecular Sensors and Ion Detection
- Fluorine in Organic Chemistry
- Carbohydrate Chemistry and Synthesis
- Lanthanide and Transition Metal Complexes
- Supramolecular Chemistry and Complexes
- Synthesis and characterization of novel inorganic/organometallic compounds
- Crystal structures of chemical compounds
- Catalytic Cross-Coupling Reactions
- Luminescence and Fluorescent Materials
- Synthesis and Catalytic Reactions
- Metal complexes synthesis and properties
- Porphyrin and Phthalocyanine Chemistry
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Coordination Chemistry and Organometallics
University of Oxford
2016-2025
Oxford Research Group
2010-2024
Western Carolina University
2020-2024
Isothermal Community College
2020-2024
The Ohio State University
2020-2024
Mansfield University
2007-2023
University of Energy and Natural Resources
2023
Institute of Crystallography
2009-2022
Oxfam
2015-2020
Piedmont International University
2020
Turning a problem to advantage: CO2, contributor global warming, was converted into the valuable resource CH3OH by adding it 2,2,6,6-tetramethylpiperidine and B(C6F5)3 in toluene under H2 (1–2 atm), heating mixture at 160 °C, vacuum distillation. formed via complex shown (C blue, N purple, O red, B orange, F green) as sole C1 product.
Because they scatter X-rays weakly, H atoms are often abused or neglected during structure refinement. The reasons why the should be included in refinement and some of consequences mistreatment discussed along with selected real examples demonstrating features for hydrogen treatment that can found software suite CRYSTALS .
Enantioenriched fluorinated heterocycles can be prepared through fluorocyclizations of prochiral indoles (see scheme; Ts=tosyl, Bn=benzyl, Boc=tert-butoxycarbonyl). More than twenty examples for this cascade fluorination–cyclization, which is catalyzed by cinchona alkaloids and employs N-fluorobenzenesulfonimide as the electrophilic fluorine source have been explored, an unprecedented catalytic asymmetric difluorocyclization has also identified. Detailed facts importance to specialist...
The charge-transfer complex generated from the combination of DABCO and sulfur dioxide, DABSO, is a bench-stable colorless solid suitable for use in organic synthesis as replacement gaseous dioxide. can be combined with Grignard reagents to form sulfinates, which then converted situ series sulfonamides. Alternatively, reaction anilines iodine leads formation sulfamides. Cheletropic addition between DABSO 2,3-dimethylbutadiene provides corresponding sulfolene.
We report the first use of solution-phase halogen bonding to control and facilitate assembly an interlocked structure through bromide anion-templated formation a rotaxane based upon iodotriazolium axle. The incorporation atom into host cavity dramatically improves anion-recognition capabilities receptor, giving unusual iodide selectivity in competitive aqueous medium.
The synthesis and anion binding properties of novel halogen-bonding (XB) bis-iodotriazole-pyridinium-containing acyclic [2]catenane host systems are described. XB receptor displays selectivity for acetate over halides with enhanced recognition compared to the analogous hydrogen-bonding (HB) receptor. A reversal in halide is observed [2]catenane, comparison receptor, due interlocked host's unique three-dimensional cavity, no oxoanions. Notable association constant values determined...
Electron-deficient heavy chalcogen atoms contain Lewis acidic σ-holes which are able to form attractive supramolecular interactions, known as bonding (ChB), with bases. However, their potential in solution-phase anion binding applications is only just beginning be realized simple acyclic systems. Herein, we explore the 5-(methylchalcogeno)-1,2,3-triazole (chalcogen = Se, Te) motif a novel ChB donor for binding. Other than being chemically robust enough incorporated into macrocyclic...
A net change: fully reversible ligand substitution involving coordination/uncoordination of gaseous water and pyrimidine induces the repetitive allosteric transformation three interpenetrated nets into a single three-dimensional net. The does not affect crystallinity sample but alters significantly spin-crossover transition; compound shows magnetic chromatic bistability (see picture).
A series of cyclometalated platinum(II) complexes have been prepared, [PtL(n)Cl], containing N--C--N-coordinating, terdentate ligands based on 1,3-dipyridylbenzene (HL(1)), incorporating aryl substituents at the central 5 position ligand. All new are intensely luminescent in a degassed solution 298 K (phi = 0.46-0.65 CH(2)Cl(2)) with lifetimes microsecond range (7.9-20.5 micros). The introduction leads to red shift lowest-energy, intense charge-transfer absorption band compared [PtL(1)Cl]...
We have synthesized a fused tetraanthracenylporphyrin by oxidation of meso-anthracenyl nickel(II) porphyrin with FeCl(3). This compound exhibits an intense red-shifted absorption spectrum (λ(max) = 1417 nm; ε 1.2 × 10(5) M(-1) cm(-1)) and small electrochemical HOMO-LUMO gap (0.61 eV). The crystal structure shows that it forms π-stacked dimers short Ni···Ni distance (3.32 Å).
Linear π-conjugated oligomers have been widely investigated, but the behavior of corresponding cyclic is poorly understood, despite recent synthesis macrocycles such as [n]cycloparaphenylenes and cyclo[n]thiophenes. Here we present an efficient template-directed a butadiyne-linked porphyrin hexamer directly from monomer. Small-angle X-ray scattering data show that this nanoring shape-persistent in solution, even without its template, whereas linear relatively flexible. The crystal structure...
A new family of electron-deficient tris(aryl)boranes, B(C(6)F(5))(3-n)(C(6)Cl(5))(n) (n = 1-3), has been synthesized, permitting an investigation into the steric and electronic effects resulting from gradual replacement C(6)F(5) with C(6)Cl(5) ligands. B(C(6)F(5))(2)(C(6)Cl(5)) (3) is accessed via C(6)Cl(5)BBr(2), itself prepared donor-free Zn(C(6)Cl(5))(2) BBr(3). Reaction C(6)Cl(5)Li BCl(3) in a Et(2)O/hexane slurry selectively produced B(C(6)Cl(5))(2)Cl, which undergoes B-Cl exchange...
Synthesis of fused bis-anthracene porphyrin monomers and dimers has been achieved by oxidative ring closure using FeCl(3) Sc(OTf)(3)/DDQ, respectively. The compounds display red-shifted absorption spectra with maxima in the near-IR at 973 1495 nm, respectively, small electrochemical HOMO-LUMO gaps. crystal structure fully shows that it a regular planar pi-system.
By employing strongly σ-donating boryl ancillary ligands, the oxidative addition of H2 to a single site Sn(II) system has been achieved for first time, generating (boryl)2SnH2. Similar chemistry can also be protic and hydridic E-H bonds (N-H/O-H, Si-H/B-H, respectively). In case ammonia (and water, albeit more slowly), shown followed by reductive elimination give an N- (or O-)borylated product. Thus, in stoichiometric fashion, redox-based bond cleavage/formation is demonstrated main group...
A combination of variable-temperature and variable-pressure single-crystal powder X-ray diffraction is used to study the thermo- piezo-mechanical properties metal–organic framework (MOF) silver(I) 2-methylimidazolate, Ag(mim). We find material exhibit a number anomalous mechanical properties: negative thermal expansion, colossal positive expansion most extreme linear compressibility yet observed for MOF. By considering response individual supramolecular motifs we are able rationalise varied...
Abstract To great (monodisperse) lengths : An improved synthesis of purer ethylene glycol (EG) oligomers allows access to 16‐ and 32‐mers pure enough for multiple incorporation, also the longest (48‐mer) discrete EG oligomer yet reported. The high purity enables first crystallizations hence glimpses secondary 3 10 ‐helical PEG structures. magnified image
Transition metal-alkane complexes-termed σ-complexes because the alkane donates electron density to metal from a σ-symmetry carbon-hydrogen (C-H) orbital-are key intermediates in catalytic C-H activation processes, yet these complexes remain tantalizingly elusive characterization solid state by single-crystal x-ray diffraction techniques. Here, we report an approach synthesis and of transition simple gas-solid reaction produce σ-complex directly. This strategy enables structural...
Chloride abstraction from the group 9 metal bis(N-heterocyclic carbene) complexes M(NHC)(2)(H)(2)Cl [M = Rh, Ir; NHC IPr N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene or IMes N,N'-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene] leads to formation of highly reactive cationic species capable dehydrogenation saturated CC and BN linkages. Thus, reaction Ir(IPr)(2)(H)(2)Cl (1) with Na[BAr(f)(4)] in fluorobenzene generates [Ir(IPr)(2)(H)(2)](+)[BAr(f)(4)](-) (4) which iridium center is...
The first catalytic route toward the title compounds by asymmetric ring-closing metathesis is described. A remarkable reversal of enantioselectivity observed when achiral imido ligand chiral molybdenum-catalyst changed (see scheme), thus highlighting importance and ligands in catalyst design. Detailed facts to specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted authors. Please note:...
Enantiomerenangereicherte fluorierte Heterocyclen können durch Fluorcyclisierungen prochiraler Indole hergestellt werden (siehe Schema; Ts=Tosyl, Bn= Benzyl, Boc=tert-Butoxycarbonyl). Mehr als 20 Beispiele dieser Fluorierungs-Cyclisierungs-Kaskade, welche von Cinchona-Alkaloiden katalysiert wird und N-Fluorbenzolsulfonimid elektrophile Fluor-Quelle nutzt, wurden untersucht. Eine katalytische asymmetrische Difluorcyclisierung war ebenfalls möglich.
Vom Schlechten zum Guten: CO2, das zur Erderwärmung beiträgt, wurde in den nützlichen Ausgangsstoff CH3OH überführt, indem es unter H2 (1–2 atm) zu 2,2,6,6-Tetramethylpiperidin und B(C6F5)3 Toluol gegeben, die Mischung auf 160 °C erhitzt im Vakuum destilliert wurde. entstand als einziges C1-Produkt über gezeigten Komplex (C blau, N violett, O rot, B orange, F grün). Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents peer-reviewed, but...
We show that KMn[Ag(CN)2]3 exhibits the strongest negative linear compressibility (NLC) effect over largest pressure range yet observed. Variable neutron powder diffraction measurements reveal its crystal lattice expands along c axis of trigonal cell under increasing hydrostatic pressure, while contracting a axis. This corresponds to "wine-rack"-like mechanism for NLC we find also results in anisotropic thermal expansion (NTE) same material. Inclusion extra-framework K+ counterions has...
A Rh(I)-catalyzed method for the efficient functionalization of arenes is reported. Aryl methyl sulfides are combined with terminal alkynes to deliver products carbothiolation. The overall process results in reincorporation original arene functional group, a sulfide, into as an alkenyl sulfide. carbothiolation can be initial alkene or alkyne hydroacylation reaction three-component cascade sequences. utility sulfide also demonstrated simple carbo- and heterocycle-forming processes. We provide...