Recent trends in chemistry, structure, and various applications of 1-acyl-3-substituted thioureas: a detailed review.

The interest in acyl thioureas has continually been escalating owing to their extensive applications in diverse fields, such as synthetic precursors of new heterocycles, pharmacological and materials science, and technology. These scaffolds exhibit a wide variety of biological activities such as antitumor, enzyme inhibitory, anti-bacterial, anti-fungal, and anti-malarial activities and find utilization as chemosensors, adhesives, flame retardants, thermal stabilizers, antioxidants, polymers and organocatalysts. In addition, the synthesis, and applications of coordination complexes of these ligands have also been overviewed.

Synthesis, conformation and Hirshfeld surface analysis of benzoxazole methyl ester as a versatile building block for heterocycles.

Solventless cyclocondensation of 2-aminothiophenol with thiourea afforded the benzo[]oxazole-2-thiol () capable of existing also in the tautomeric form benzo[]oxazole-2(3)-thione (). Acylation with methyl chloroacetate in dry ethanol in absence of any base or catalyst selectively afforded the -substituted ester 2-(methoxycarbonylmethylthio)benzo[]oxazole () in preference to the corresponding -substituted ester -(methoxycarbonylmethyl)thioxobenzoxazole (). Quantum chemical calculations were conducted to determine the conformational landscape and NBO population analysis showed the strong electronic delocalization resonance interactions on the 2-mercaptobenzaxazole group.

Investigation of stable solid diazonium salt by molecular structure, Hirshfeld surface analysis, optical and electrochemical studies, and applications.

The title compound is a new pyrazolone derivative which was synthesized starting from p-sulphophenyl-3-methyl-5-pyrazolone (1) by nitrosation at low temperature to afford the corresponding p-sulphophenyl-3-methyl-4-nitroso-5-pyrazolone which can exist both in nitroso (2a) and oxime tautomeric forms (2b). Reduction of the latter using zinc with hydrochloric acid furnished the 4-amino-p-sulphophenyl-3-methyl-5-pyrazolone (3). The diazotization of (3) under careful control of temperature and pH afforded the p-sulphophenyl-3-methyl-5-pyrazolone diazonium salt (4) which was re-crystallized from acidified ethanol to afford crystal suitable for X-ray studies.

Pt-Ni@PC900 Hybrid Derived from Layered-Structure Cd-MOF for Fuel Cell ORR Activity.

Fuel cell technology is the supreme alternate option for the replacement of fossil fuel in the current era. Pt alloys can perform well as fuel cell electrodes for being used as catalytic materials to perform the very notorious oxygen reduction reaction. In this regard, first, a layered metal-organic framework with empirical formula [CHCdO] ·4HO is synthesized and characterized using various experimental and theoretical techniques.

Synthesis, Crystal Structure, Hirshfeld Surface Analysis, DFT, and DNA-Binding Studies of (E)-2-(3-Hydroxy-4-Methoxybenzylidene)Hydrazinecarbothioamide.

(E)-2-(3-Hydroxy-4-methoxybenzylidene)hydrazinecarbothioamide 3 was synthesized by reacting thiosemicarbazide with 2-hydorxy-3-methoxybenzaldehyde in dry ethanol. The structure was elucidated by spectroscopic (FT-IR, H NMR, and C NMR) and single crystal X-ray diffraction techniques. A detailed analysis of the intermolecular interactions has been performed based on the Hirshfeld surfaces and their associated two-dimensional fingerprint plots.

Experimental and Theoretical High Energy Resolution Hard X-ray Absorption and Emission Spectroscopy on Biomimetic CuS Complexes.

High energy resolution fluorescence detected X-ray absorption near edge structure (HERFD-XANES) and Valence-to-Core X-ray emission (VtC-XES) spectroscopy are established as hard X-ray methods to investigate complexes that might be relevant as mimics for the biologically important Cu site. By investigation of three carefully selected complexes of the type [Cu(NGuaS)X], characterized by a cyclic CuS core portion and a varying adjunct ligand nature, it is proven that the HERFD-XANES and VtC-XES measurements in combination with extensive TD-DFT calculations can reveal details of the electronic states in such complexes, including HOMO and LUMO levels and spin states. By theoretical spectroscopy, the value of this methodic combination for future in situ studies is demonstrated.

Synthesis, single crystal analysis, biological and docking evaluation of tetrazole derivatives.

Tetrazoles are conjugated nitrogen-rich heterocycles considered as bio-isosteres of carboxylic acids. Tetrazoles owing to their conjugated structures serve as biologically relevant potent scaffolds. The present research paper reports the successful synthesis and single crystal analysis of three different tetrazole derivatives .

Borane-Catalyzed Synthesis of Quinolines Bearing Tetrasubstituted Stereocenters by Hydride Abstraction-Induced Electrocyclization.

The borane-catalyzed synthesis of quinoline derivatives bearing tetrasubstituted stereocenters from vinyl anilines has been developed. Mechanistic studies and quantum-mechanical investigations support the hydride abstraction/electrocyclization/hydride addition mechanism. The products were obtained in up to 99 % yield with a diastereoselectivity of >99 % in favour for the 3a-5-cis isomer.

One-pot synthesis, quantum chemical calculations and X-ray diffraction studies of thiazolyl-coumarin hybrid compounds.

Two closely related hybrid species containing both, thiazolyl and coumarin groups, were synthesized by using two different one-pot procedures from a common precursor. The reaction of α-bromoacetylcoumarin with thioacetamide in methanol furnished 3‑(2‑methylthiazol‑4‑yl)‑2H‑chromen‑2‑one (2), whereas refluxing α‑bromoacetylcoumarin with potassium thiocyanate in ethanol afforded 3‑(2‑ethoxythiazol‑4‑yl)‑2H‑chromen‑2‑one (3). Both derivatives were fully characterized by spectroscopic methods, elemental analysis and X-ray diffraction studies.

The Connection between NHC Ligand Count and Photophysical Properties in Fe(II) Photosensitizers: An Experimental Study.

Four homo- and heteroleptic complexes bearing both polypyridyl units and N-heterocyclic carbene (NHC) donor functions are studied as potential noble metal-free photosensitizers. The complexes [Fe(L1)(terpy)][PF], [Fe(L2)][PF], [Fe(L1)(L3)][PF], and [Fe(L3)][PF] (terpy = 2,2':6',2″ terpyridine, L1 = 2,6-bis[3-(2,6-diisopropylphenyl)imidazol-2-ylidene]pyridine, L2 = 2,6-bis[3-isopropylimidazol-2-ylidene]pyridine, L3 = 1-(2,2'-bipyridyl)-3-methylimidazol-2-ylidene) contain tridentate ligands of the C^N^C and N^N^C type, respectively, resulting in a Fe-NHC number between two and four. Thorough ground state characterization by single crystal diffraction, electrochemistry, valence-to-core X-ray emission spectroscopy (VtC-XES), and high energy resolution fluorescence detected X-ray absorption near edge structure (HERFD-XANES) in combination with ab initio calculations show a correlation between the geometric and electronic structure of these new compounds and the number of the NHC donor functions.

Borane-catalyzed indole synthesis through intramolecular hydroamination.

The reaction of 2-alkynyl anilines with catalytic amounts of B(CF) (5 mol%) resulted in the formation of 2-substituted indoles according to an intramolecular hydroamination in good to excellent yields. Reaction intermediates as well as products were characterized by NMR spectroscopy and by X-ray crystallography. The domino hydroamination/hydrogenation sequence allowed the efficient synthesis of tetrahydroquinoline 8 in good yield.

Heteroacene Synthesis through C-S Cross-Coupling/5-endo-dig Cyclization.

Highly efficient, one-step synthesis of sulfur-containing heteroacenes was achieved through palladium-catalyzed C-S cross-coupling of bis-alkynes with thioacetate as hydrogen sulfide surrogate. Heteroacenes consisting of three, five, and seven fused aromatic rings were obtained in a single catalytic step by four-, six-, and eightfold C-S bond formation.

Frustrated Lewis Pair Catalyzed Dehydrogenative Oxidation of Indolines and Other Heterocycles.

An acceptorless dehydrogenation of heterocycles catalyzed by frustrated Lewis pairs (FLPs) was developed. Oxidation with concomitant liberation of molecular hydrogen proceeded in high to excellent yields for N-protected indolines as well as four other substrate classes. The mechanism of this unprecedented FLP-catalyzed reaction was investigated by mechanistic studies, characterization of reaction intermediates by NMR spectroscopy and X-ray crystal analysis, and by quantum-mechanical calculations.

A Comprehensive Study of Copper Guanidine Quinoline Complexes: Predicting the Activity of Catalysts in ATRP with DFT.

Copper complexes of the hybrid guanidine ligands 1,3-dimethyl-N-(quinolin-8-yl)-imidazolidin-2-imine (DMEGqu) and 1,1,3,3-tetramethyl-2-(quinolin-8-yl)-guanidine (TMGqu) have been studied comprehensively with regard to their structural and electrochemical properties and their activity in atom transfer radical polymerization (ATRP). A simple analysis of the molecular structures of the complexes gives no indication about their activity in ATRP; however, with the help of DFT and NBO analysis the influence of particular coordinating donors on the electrochemical properties could be fully elucidated. With an adequate DFT methodology and newly applied theoretical isodesmic reactions it was possible to predict the relative position of the redox potentials of copper complexes containing DMEGqu and TMGqu ligands.

Frustrated Lewis Pair-Catalyzed Cycloisomerization of 1,5-Enynes via a 5-endo-dig Cyclization/Protodeborylation Sequence.

The first frustrated Lewis pair-catalyzed cycloisomerization of a series of 1,5-enynes was developed. The reaction proceeds via the π-activation of the alkyne and subsequent 5-endo-dig cyclization with the adjacent alkene. The presence of PPh3 was of utmost importance on the one hand to prevent side reactions (for example, 1,1-carboboration) and on the other hand for the efficient protodeborylation to achieve the catalytic turnover.

Crystal structure of tris-(1,3-dimesityl-4,5-di-hydro-1H-imidazol-3-ium) tetra-bromido-cobaltate(II) bromide chloro-form hexa-solvate.

In the unit cell of the title compound, (C21H27N2)3[CoBr4]Br·6CHCl3, the tetrabromidocobaltate(II) anion and the bromide anion are located on a crystallographic threefold rotation axis. For the [CoBr4](2-) group, the axis runs through one of the Br ligands and the Co(II) atom. All other structure moieties lie on general sites.

Crystal structure of di-bromido-bis-(1,3-dibenzyl-1,3-diazinan-2-one-κO)cobalt(II).

The unit cell of the title complex, [CoBr2(C18H20N2O)2], contains 1.5 formula units per asymmetric unit with one mol-ecule sitting on a general site and a second one halved by a crystallographic twofold rotation axis passing through the Co(II) cation. Both Co(II) atoms are coordinated in a distorted tetra-hedral manner by two Br(-) ligands and two O atoms of the pyrimidinone (OPyr) groups.

Crystal structure of di-chlorido-bis-(1,3,4,5-tetra-methyl-1H-imidazol-2-ium-2-thiol-ate-κS)nickel(II).

In the mol-ecular structure of the title compound, [NiCl2(C7H12N2S)2], the Ni(II) atom has a distorted tetra-hedral geometry, coordinated by two Cl atoms [Ni-Cl= 2.2336 (6) Å] and two thione S atoms [Ni-S= 2.3024 (6) Å].

Crystal structures of di-iodido-bis-[(1S,5S)-4-mesityl-1,2,8,8-tetra-methyl-2,4-di-aza-bicyclo-[3.2.1]octan-3-yl-idene-κC (3)]palladium(IV) and di-chlorido-[(1S,5S)-4-mesityl-1,2,8,8-tetra-methyl-2,4-di-aza-bicyclo[3.2.1]octan-3-yl-idene-κC (3)](tri-phenyl-phosphane-κP)palladium(IV).

The mol-ecular structures of the chiral title compounds, [Pd(C19H28N2)2I2], (I), and [Pd(C19H28N2)Cl2(C18H15P)], (II), show a distorted square-planar coordination around the Pd(II) atoms with two halogenide (Hal) ligands each and two N-heterocyclic carbene (NHC) ligands in (I) or one NHC and one tri-phenyl-phosphane ligand in (II). The deviations of the Pd(II) atoms from the L 2Hal2 best plane (L = NHC or tri-phenyl-phosphane ligand) are 0.206 (1) Å for (I) and 0.

A combined experimental and theoretical study of the tautomeric and conformational properties of (5-phenyl-tetrazol-2-yl)-acetic acid methyl ester.

The tautomeric and conformational properties of a new tetrazole derivative are studied in a combined approach that includes the analysis of the experimental vibrational data together with theoretical calculation methods, especially in terms of natural bond orbital (NBO) population analysis. Moreover, the molecular and crystal structure was determined by single crystal X-ray diffraction. The compound crystallized as the 2-tautomeric form, monoclinic space group P21/c with Z=4, a=10.

Crystal structure of bis-[1,3,4,5-tetra-methyl-1H-imidazole-2(3H)-thione-κS]chlorido-copper(I).

The mol-ecular structure of the title compound, [CuCl(C7H12N2S)2], shows a slightly distorted trigonal-planar coordination geometry of the Cu atom. The Cu-Cl bond measures 2.2287 (9) Å, and the two Cu-S bonds are significantly different from each other, with values of 2.

Coordination Chemistry of Cyclic Disilylated Germylenes and Stannylenes with Group 11 Metals.

Reactions of EtP adducts of bissilylated germylenes and stannylenes with gold, silver, and copper cyanides led to cyanogermyl or -stannyl complexes of the respective metals. In the course of the reaction the phosphine moved to the metal, while the cyanide migrated to the low-coordinate group 14 element. The respective gold complexes were found to be monomeric, whereas the silver and copper complexes exhibited a tendency to dimerize in the solid state.

Crystal structure of di-chlorido-bis-(1,3-diisopropyl-4,5-dimethyl-2H-imidazole-2-thione-κS)zinc(II).

The mol-ecular structure of the title compound, [ZnCl2(C11H20N2S)2], shows tetra-hedral Zn coordination from two Cl ligands and two thione groups. The Zn-Cl bond lengths differ sligthly at 2.2310 (10) and 2.

Crystal structure of 2,2'-({[2-(trityl-sulfan-yl)benz-yl]azane-diyl}bis-(ethane-2,1-di-yl))bis-(isoindoline-1,3-dione).

In the structure of the title compound, C46H37N3O4S, the planes of the two isoindoline units make a dihedral angle of 77.86 (3)°. The dihedral angles between the benzyl plane and the isoindoline units are 79.

Bis{2-[(Tri-phenyl-meth-yl)amino]-phen-yl} diselenide aceto-nitrile monosolvate.

The mol-ecular structure of the title compound, C50H40N2Se2·C2H3N, shows a syn conformation of the benzene rings bound to the Se atoms, with an Se-Se bond length of 2.3529 (6) Å and a C-Se-Se-C torsion angle of 93.53 (14)°.