A5068803066- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Crystallography and molecular interactions
- Inorganic Fluorides and Related Compounds
- Inorganic Chemistry and Materials
- Fluorine in Organic Chemistry
- Organometallic Complex Synthesis and Catalysis
- Advanced Chemical Physics Studies
- Energetic Materials and Combustion
- Chemical Reactions and Mechanisms
- Synthesis and characterization of novel inorganic/organometallic compounds
- Carbon dioxide utilization in catalysis
- CO2 Reduction Techniques and Catalysts
- Catalytic Cross-Coupling Reactions
- Synthesis and Reactions of Organic Compounds
- Magnetism in coordination complexes
- Molecular Spectroscopy and Structure
- Metal-Organic Frameworks: Synthesis and Applications
- Thermal and Kinetic Analysis
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Organic Light-Emitting Diodes Research
- Perovskite Materials and Applications
- Ionic liquids properties and applications
- Machine Learning in Materials Science
- Crystal structures of chemical compounds
University of Southern California
2016-2025
Southern California University for Professional Studies
2014-2025
Los Angeles City College
2015-2020
St Petersburg University
2014
University of Lethbridge
2012
Ludwig-Maximilians-Universität München
2008
KU Leuven
2008
University of Alabama
2006-2008
Edwards Air Force Base
2002-2006
University of California, Riverside
2002-2004
Helping copper glow Copper's abundance makes the metal an appealing candidate for luminescence applications. However, many complexes tend to decay nonradiatively after photoexcitation. A recently described exception involves a two-coordinate complex that sandwiches between amide ligand and carbene ligand. Hamze et al. thoroughly explored this motif measured nearly perfect efficiency. They used property produce prototype blue organic light-emitting diode. The photodynamics appeared largely...
Singlet fission is a process in which singlet exciton converts into two triplet excitons. To investigate this phenomenon, we synthesized covalently linked 5-ethynyl-tetracene (ET) dimers with differing degrees of intertetracene overlap: BET-X, large, cofacial overlap tetracene π-orbitals, and BET-B, twisted arrangement between tetracenes exhibits less the π-orbitals. The compounds were crystallographically characterized studied by absorption emission spectroscopy solution, PMMA neat thin...
A systematic study is presented on the physical and photophysical properties of isoelectronic isostructural Cu, Ag, Au complexes with a common amide (N-carbazolyl) two different carbene ligands (i.e., CAAC = (5 R,6 S)-2-(2,6-diisopropylphenyl)-6-isopropyl-3,3,9-trimethyl-2-azaspiro[4.5]decan-2-ylidene, MAC 1,3-bis(2,6-diisopropylphenyl)-5,5-dimethyl-4-keto-tetrahydropyridylidene). The crystal structures (carbene)M(I)(N-carbazolyl) (MCAAC) (MAC)M(I)(N-carbazolyl) (MMAC) show coplanar carbzole...
We report here the efficient reduction of CO2 to CO by cobalt aminopyridine macrocycles. The effect pendant amines on catalysis was investigated. Several complexes based azacalix[4](2,6)pyridine framework with different substitutions amine groups have been synthesized (R = H (1), Me (2), and allyl (3)), their electrocatalytic properties were explored. Under an atmosphere in presence weak Brønsted acids, large catalytic currents are observed for 1, corresponding excellent Faradaic efficiency...
The bioinspired incorporation of pendant proton donors into transition metal catalysts is a promising strategy for converting environmentally deleterious CO2 to higher energy products. However, the mechanism transfer in these systems poorly understood. Herein, we present series cobalt complexes with varying secondary and tertiary amines ligand framework aim disentangling roles first second coordination spheres reduction catalysis. Electrochemical kinetic studies indicate that rate catalysis...
Layered black phosphorus (BP) has attracted wide attention for mid-infrared photonics and high-speed electronics, due to its moderate band gap high carrier mobility. However, intrinsic of around 0.33 electronvolt limits the operational wavelength range BP photonic devices based on direct interband transitions 3.7 μm. In this work, we demonstrate that arsenic alloy (b-As xP1- x) formed by introducing into can significantly extend devices. The as-fabricated b-As0.83P0.17 photodetector...
Amine-assisted homogeneous hydrogenation of CO2 to methanol is one the most effective approaches integrate capture with its subsequent conversion CH3OH. The typically proceeds in two steps. In first step amine formylated via an situ formed alkylammonium formate salt (with consumption 1 equiv H2). second generated formamide further hydrogenated 2 more H2 CH3OH while regenerating amine. present study, we investigated effect molecular structure ruthenium pincer catalysts and amines that are...
Abstract The trifluoromethanide anion is the postulated key intermediate in nucleophilic trifluoromethylation reactions. However, for more than six decades, was widely believed to exist only as a short‐lived transient species condensed phase. It has now been prepared bulk first time THF solution. with [K(18‐crown‐6)] + cation unequivocally characterized by low‐temperature 19 F and 13 C NMR spectroscopy. Its intermediacy reactions directly evident its reaction chemistry various electrophilic...
A series of three phosphorescent mononuclear (NHC)-Cu(I) complexes were prepared and characterized. Photophysical properties found to be largely controlled by the NHC ligand chromophore. Variation leads emission colour tuning over 200 nm range from blue red, efficiencies 0.16-0.80 in solid state.
Abstract Due to the intermittent nature of most renewable energy sources, such as solar and wind, storage is increasingly required. Since electricity difficult store, hydrogen obtained by electrochemical water splitting has been proposed an carrier. However, handling transportation in large quantities itself a challenge. We therefore present here method for based on CO 2 (HCO 3 − )/H formate equilibrium. This amine‐free efficient reversible system (>90 % yield both directions) catalyzed...
The incorporation of homogeneous catalysts for CO2 reduction into extended frameworks has been a successful strategy increasing catalyst lifetime and activity, but the effects linkers on catalysis are underexplored. In this work, novel rhenium bipyridine complex was synthesized purpose designing covalent-organic framework (COF) with both metalloporphyrin metal moieties. Investigation as shows faradaic efficiency 81(8)% electrocatalytic conversion to CO upon addition methanol proton source....
We report new derivatives of symmetric squaraine dyes with N,N-diarylanilino substituents that have high solubility and absorptivity (ε = 0.71–4.1 × 105 M–1 cm–1) in the red solar spectral region (λmax 645–694 nm) making them promising candidates for application organic photovoltaics (OPVs). Unsymmetrical N,N-diisobutylanilino- N,N-diphenylanilino(diphenylamino)squaraines also been prepared give blue-shifted absorption spectra 529–535 relative to their counterparts. Compared...
A series of four neutral luminescent three-coordinate Cu(I) complexes (IPr)Cu(N∧N), where IPr is a monodentate N-heterocyclic carbene (NHC) ligand (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) and N∧N denotes monoanionic pyridyl-azolate ligands, have been synthesized characterized. monomeric, geometry, best described as distorted trigonal planar, has established by single-crystal X-ray analyses for three the derivatives. In contrast to previously reported (IPr)Cu(N∧N) complexes,...
A convenient access to 5-(trinitromethyl)-2H-tetrazole (HTNTz) has been developed, based on the exhaustive nitration of 1H-tetrazole-5-acetic acid, which was prepared from ethyl cyanoacetate and HN3 in a 1,3-dipolar cycloaddition reaction, followed by basic hydrolysis. HTNTz converted into ammonium, guanidinium, rubidium, cesium, copper, silver 5-(trinitromethyl)-2H-tetrazolates. In addition, ammonia adducts copper salts were isolated. The reaction with hydrazine hydroxylamine resulted...
A series of (carbene)Au(I)(aryl) complexes are reported. The nature the lowest excited state in these changes character from metal-to-ligand charge transfer (MLCT) to interligand (ICT) with increasing electron-donating strength aryl ligand. Complexes that have MLCT undergo a Renner–Teller bending distortion upon excitation. Such leads large rate nonradiative decay, on order 108 s–1. Renner–Teller-based decay does not occur chromophores an ICT emissive state. Introducing julolidine moiety and...
The reduction of CO2 into higher energy products such as carbon-based fuels and feedstocks is an attractive strategy for mitigating the continuous rise in emissions associated with growing global demand. Rhenium tricarbonyl complexes bearing 2,2'-bipyridine (2,2'-bpy) ligands are well-established molecular electrocatalysts selective to CO. Construction efficient devices this electrochemical process requires immobilization electrode surfaces. To integrate Re(2,2'-bpy)(CO)3 fragments a...
23 nitrogens and only one phosphorus: The N5+ ion is combined with energetic anions in the form of [P(N3)6]− [B(N3)4]− (see scheme), containing 91 96 wt %, respectively, nitrogen. Also, thermally unstable compound N5HF2⋅n HF prepared by metathesis from N5SbF6 CsHF2. Its usefulness as a reagent for synthesis new salts demonstrated preparation N5PF6, N5BF4, N5SO3F. This direct route restricted small number [N2F]+ available. Except N2FAsF6 N2FSbF6 reports on N2FBF419 N2FPF620 salts, no other...
Direct N-difluoromethylation of imidazoles and benzimidazoles has been achieved using TMS-CF3 (the Ruppert-Prakash reagent) under neutral conditions. Difluoromethylated products were obtained in good-to-excellent yields. Inexpensive, commercially available starting materials, conditions, shorter reaction times are advantages this methodology. Reactions accessible through conventional as well microwave irradiation
Formic acid is decomposed to H2 and CO2 in the presence of RuCl3 triphenylphosphines an emulsion. In situ formed ruthenium carbonyls, such as [Ru(HCO2)2(CO)2(PPh3)2] (1), [Ru(CO)3(PPh3)2] (2), [Ru2(HCO2)2(CO)4(PPh3)2] (3), a large cluster, involving Ru12 core, were identified structurally characterized from reaction mixtures. The catalytic activity mono binuclear complexes was also investigated it found that (3) shows high stability even at elevated temperatures pressures its 1 order...
Transition metal perovskite chalcogenides (TMPCs) are explored as stable, environmentally friendly semiconductors for solar energy conversion. They can be viewed the inorganic alternatives to hybrid halide perovskites, and chalcogenide counterparts of oxides with desirable optoelectronic properties in visible infrared part electromagnetic spectrum. Past theoretical studies have predicted large absorption coefficient, defect characteristics, bulk photovoltaic effect TMPCs. Despite recent...
The structural, photophysical and electrochemical properties of three luminescent 2-coordinate coinage metal (i.e. M = Cu, Ag, Au) complexes bearing a sterically bulky benzimidazolyl carbene, 1,3 bis(2,6 diisopropylphenyl)-1-H-benzo[d]imidazol-2-ylidene (BZI), carbazolide (Cz) as the anionic ligand were investigated. All emit in deep blue region (~430 nm) with relatively narrow (full width at half maximum 44 nm, 2300 cm-1) vibronic fine structure nonpolar media (methylcyclohexane room...
Crystalline solids exhibiting glass-like thermal conductivity have attracted substantial attention both for fundamental interest and applications such as thermoelectrics. In most crystals, the competition of phonon scattering by anharmonic interactions crystalline imperfections leads to a non-monotonic trend with temperature. Defect-free crystals that exhibit glassy low monotonic increase temperature are desirable because they intrinsically thermally insulating while retaining useful...