Molecular Structures Of 2a Research Articles

Addition of diazonium salts to the coordinatively unsaturated core of a dinuclear organoruthenium complex

Abstract The reaction of [Ru2(CO)4(µ-H)(µ-PtBu2)(µ-Ph2PCH2PPh2)] (1) with the diazonium salts [PhN2]BF4 and [p-BrC6H4N2]BF4 in dichloromethane at T = 273 K was investigated. The oxidative addition afforded the products [Ru2(CO)4(µ-H)(µ-PtBu2)(µ-Ph2PCH2PPh2)(µ-N2Ph)]BF4 (2a) and [Ru2(CO)4(µ-H)(µ-PtBu2)(µ-Ph2PCH2PPh2)(µ-N2C6H4-p-Br)]BF4 (2b) in good yields. The products have been characterized by NMR and IR spectroscopy and mass spectrometry and the molecular structure of 2a has been determined by a single-crystal X-ray diffraction analysis (monoclinic, space group P21/m, Z = 2).

Unravelling the kinetics of electro- and photochemical S → O linkage isomerization in Ru(II)-NHC-DMSO complexes utilised for photoinduced substitution reactions.

Our recently reported Ru(III)-NHC complexes 1a and 1b were utilized as suitable precursors to prepare new Ru(II)-NHC-(DMSO)2 complexes 2a and 2b. Complexes 2a and 2b reacted with 2,2'-bipyridine to give complexes 3a and 3b, respectively, with substitution of only one of the DMSO ligands. All new complexes were characterized using various spectroscopic techniques and the molecular structures of 2a and 3a were determined using single-crystal X-ray diffraction technique. Complexes 2a, 2b, 3a, and 3b showed the S → O linkage isomerization of the DMSO ligand upon oxidation of the Ru centre from +II to +III, as confirmed by the thermodynamic and kinetic data obtained from cyclic voltammetry experiments. It was observed that in the bisdimethylsulfoxide complexes 2a and 2b, only one DMSO ligand isomerized, which was further corroborated by the computational studies performed to optimize the geometry of the possible linkage isomers of complexes 2a and 3a in +2 and +3 oxidation states, whereas complexes 3a and 3b showed a high preference for the O-bound isomer in the Ru(III) redox state. The role of NHC in stabilizing the mixed isomer in complexes 2a and 2b and preventing the isomerization of both DMSO ligands coordinated to the Ru centre was studied; moreover, NHC provided good solvent compatibility for photochemical S → O isomerization in all the complexes. Taking advantages of the photoinduced linkage isomerization in 2a and 2b, the synthesis of 3a and 3b was revisited and performed using 2a and 2b, respectively, following a photoinduced substitution reaction in the presence of 2,2'-bipyridine. The kinetics of the reversion from the O-bound to S-bound isomer was found to follow the DMSO-assisted intermolecular S → O isomerization pathway.

Cationic ruthenium(II)-CNC pincer complexes as phosphine-free catalysts for nitrile hydration to amides in aqueous medium

We report the synthesis, characterization, and catalytic activity of a series of electron-rich, phosphine-free complexes featuring multiple N-heterocyclic carbene (NHC) ligands, namely [Ru(CNCi-Pr)(CNMe)I]PF6 (1a), [Ru(CNCi-Pr)(CNi-Pr)I]PF6 (1b), [Ru(CNCCy)(CNMe)I]PF6 (2a), [Ru(CNCCy)(CNi-Pr)I]PF6 (2b), [Ru(CNCt-Bu)(CNMe)I]PF6 (3a), and [Ru(CNCt-Bu)(CNi-Pr)I]PF6 (3b) (where CNC = 2,6-bis(alkylimidazol-2-ylidene)-pyridine and CN = 2-(3-alkylimidazol-2-ylidene)-pyridine). Spectroscopic characterization using multinuclear NMR and high-resolution mass spectrometry (HRMS) confirms the composition of all complexes. The molecular structures of 1a and 2a were further confirmed by single-crystal X-ray diffraction. The catalytic activity of these ruthenium(II) complexes in the hydration of nitriles under mild reaction conditions and in the aqueous medium have been explored, with complex 1a exhibiting superior reactivity among the studied complexes. Mechanistic investigations revealed a catalytic pathway initiated by a [Ru-OH] species, facilitated by the hemilability of a pyridine ligand. The versatility of these ruthenium(II) complexes as catalysts for nitrile hydration has been demonstrated through successful conversions of a diverse range of nitriles, containing electron-releasing or electron-withdrawing groups, and heterocyclic nitriles into the corresponding amides with high reactivity and good to excellent yields.

Multicomponent click reactions catalyzed by copper(I) complex bearing Bis(imino)pyridine-phosphine ligands

Copper(I)-bis(imino)pyridine-triphenylphosphine complex (2a) was prepared from the reaction of bis(imino)pyridine ligand and [Cu(PPh3)3Cl]. The tetracoordinated copper(I) complex was characterized by UV–Visible, NMR and elemental analysis. The molecular structure of 2a was characterized by single crystal X-ray diffraction and adopts a distorted tetrahedral geometry around the copper centre. The copper(I) 2a was established as catalyst for one-pot multicomponent Click reaction of aryl halides and sodium azide with terminal alkynes using 0.5 mol % catalyst loading in methanol as a solvent. Several 1,4-disubstituted 1,2,3-triazoles have been synthesized in moderate to excellent yields.

Piano stool iron complexes with isocyanide ligands

Complexes [FeCpI(CO)(CNR)] [2a-f; R = 2,6-C6H3Me2 = Xyl, 4-C6H4OMe, CH2Ph, CH2P(O)(OEt)2, CH2SO2(4-C6H4Me), Me; Cp = η5-C5H5] and [FeCpI(CNR)2] [3a-f; R = Xyl, 4-C6H4OMe, CH2Ph, CH2P(O)(OEt)2, Me] were obtained in 58-73% yields from the thermal reactions of [FeCpI(CO)2] (1) in toluene with one/two equivalents of CNR, respectively, in the presence of [Fe2Cp2(CO)4] as catalyst. The 1:2 molar reaction of 1 with CNMe resulted in the prevalent formation of [FeCp(CO)(CNMe)2]I, 4f (86% yield). The reactions of 1 and 3a-c with an excess of CF3SO3CH3 afforded the triflate adducts [FeCp(OSO2CF3)L2] (L = CO, 1TF; Xyl, 3aTF; 4-C6H4OMe, 3bTF; CH2Ph, 3cTF), in 62-78% yields, via CH3I elimination. All products were characterized by elemental analysis, IR and multinuclear NMR spectroscopy, moreover the molecular structures of 2a, 2e and 3a were ascertained by single crystal X-ray diffraction. The potential of 1, 2a-f and 3a-f as catalysts in the bulk polymerization of rac-lactide was examined.

Synthesis, spectral and structural characterization of iron chalcogenomalonato complexes CpFe(CO)2ECOCH2CO2R (E = S, Se)

The synthesis of CpFe(CO)2ECOCH2CO2R [E = S (1), Se (2); R = Me (a), Et (b)] was achieved by treating (µ-E x )[CpFe(CO)2]2 (E = S, x = 2–4, Se, x = 1) with alkyl malonyl chlorides at ambient temperature. The synthesized compounds were characterized by elemental analysis, FT-IR, 1H and 13C NMR spectroscopy as well as with UV–Vis spectroscopic techniques. The molecular structures of 1a and 2a were determined by single crystal X-ray diffraction studies and reveal that the two compounds are monomeric in the solid state with the iron center located in a distorted octahedral environment.

Synthesis and antifungal and antibacterial bioactivities of diborolanes containing arylamines

A good yield of 1,2-diarylamino-1,2-diborolanes 2 was obtained from the reaction of 1,2-dichloro-1,2-diborolane 1 and ArNHLi (an anilide). The structures of these new derivatives were characterized by nuclear magnetic resonance spectroscopy. The molecular structures of 2a and 2b were also determined using single-crystal X-ray diffraction. Antimicrobial activities of synthesized compounds against some Gram-positive and -negative bacteria and yeasts were determined. Some compounds were found to have strong antibacterial and antifungal properties, especially against the bacterium, S. pneumonia, which is the causative agent of pneumonia, and the fungus, C. albicans, which is the causative agent of candidiasis. The compounds 2a and 3 had a powerful effect (compound 2a and 3 = 1 μgmL−1) against S. pneumoniae ATCC 27336 bacteria. In addition, compounds 2a, 3 and 2f were observed to have strong effects (compound 2a, 3, 2f = 2 μgmL−1) against C. albicans ATCC 10231 and C. utilis ATCC 9950. The results obtained were found to be more effective than the MIC values (128–64 μgmL−1) of Streptomycin and Flukanozol drugs used for bacteria and yeasts. The results of our study show that the synthesized substances can be used for new drug applications that are being developed against infectious diseases in the pharmaceutical industry.

A convenient synthesis, in silico study and crystal structure of novel sulfamidophosphonates: Interaction with SARS-CoV-2

A one-pot synthetic strategy was developed for the synthesis of novel sulfamidophosphonates via a three-component Kabachnik-Fields reaction of sulfanilamide, triethyl phosphite, and various aldehyde using ultrasound irradiation. Seven organophosphorus derivatives were synthesized with high yields through this newly developed method. The target compounds were characterized by 1H, 31P, 13C NMR, and IR. The molecular structure of 4a was obtained by X-ray diffraction on the monocrystal. Crystal belongs to the orthorhombic system with space groups Pbca. Insight into the binding mode of the synthesized compounds (ligand) into the binding sites of SARS-CoV2 (PDF code: 5R80) was provided by docking studies, performed with the help of Maestro 9.0 docking software.

Substitution of the chlorido ligand for PPh3 in anticancer organoruthenium complexes of sulfonamide-functionalized pyridine-2-carbothioamides leads to high cytotoxic activity

The functionalization of Ru(arene) complexes with bioactive moieties is a promising approach for modulating their biological properties. This strategy may result in compounds with synergistic biological effects which may be capable of overcoming major drawbacks of currently used chemotherapeutics. A series of RuII(η6-p-cymene)Cl complexes 1a–1c comprising sulfonamide and pyridine-2-carbothioamide (PCA) ligands were designed to evaluate their antiproliferative potency in cancer cells. The ligands and their corresponding organoruthenium complexes were characterized by NMR spectroscopy, elemental analysis, ESI-MS analysis and the molecular structure of 1a was determined by X-ray diffraction analysis. In vitro cytotoxic assays showed that the chlorido complexes 1a–1c are inactive. However, the cytotoxicity was significantly improved when the labile chlorido ligand was replaced with triphenylphosphine in 2a–2c. The most active complex 2c showed IC50 values as low as 1.9 ± 0.5 µM in cervical carcinoma SiHa cells compared to 3.0 ± 1.1 µM for the chemotherapeutic agent cisplatin.

Synthesis, characterization, 31P{1H} NMR, X-ray structure and voltammetric study of 2-mercaptothiazolines and phosphines ruthenium(II) complexes

In this work, complexes containing mercaptothiazolines, and mono- and diphosphines with the general formula [Ru(N−S)2(P)2] or [Ru(N−S)2(P-P)] – N–S−: 1,3-thiazoline-2-thionate (tzt− - a) and benzo-1,3-thiazoline-2-thionate (bzoxt− - b), and P2 = monophosphine: P{p-tol}3 – 2; P-P = dppe – 3, dppp – 4, dppb – 5, dppf – 6 or DPEPhos – 7 were synthesized. The complexes were characterized by 1H and 31P NMR, vibrational spectroscopy, elemental analysis, and the molecular structures of 3a, 4a, 5a, 6a•CH2Cl2 and 7a were solved by X-ray diffraction. The Hirshfeld surface analysis and the 2D fingerprint plots were performed. The 1H NMR spectra of the compounds revealed the signals of the ligands and the main feature is the absence of the NH signal of the protonated ligands TztH and BzoxtH supporting the coordination in their anionic forms, which is also evidenced by the vibrational spectroscopy and molar conductivity studies. The 31P{1H} NMR spectra present only one singlet indicating the chemical equivalence of both phosphorus nuclei and in a region compatible with phosphorus cis-positioned for the P(p-tol)3 and for the potentially trans-spanning dppf and DPEPhos, whereas for the other diphosphines (dppe, dppp and dppb) only the cis-configuration is expected. The molecular structure revealed the Ru center is sited on a distorted octahedral geometry mainly as a consequence of the formation of four-membered chelate rings involving the N–S− ligand. The coordination sphere is completed with two phosphorus atoms positioned in a cis-fashion while trans to the nitrogen atoms of the tzt− ligand, and the remaining sulfur donors (thiolate) of tzt− ligand positioned trans to each other. The cyclic voltammograms of the complexes presented one monoelectronic and reversible process attributed to the Ru3+/Ru2+ couple, and for the complexes with dppf an additional redox process is observed due to the Fe3+/Fe2+ couple.

Synthesis and Characterization of a Series of Diarylgermylenes and Dihalodigermenes Having Fused-Ring Bulky “Rind” Groups

Abstract A series of diarylgermylenes, (Rind)2Ge: (1) [Rind = EMind (a), Eind (b), and MPind (c)], bearing the fused-ring bulky 1,1,3,3,5,5,7,7-octa-R-s-hydrindacen-4-yl (Rind) groups has been obtained as purple to blue crystals by the reaction of GeCl2·dioxane with 2 equiv. of (Rind)Li. A similar reaction using 1 equiv. of (Rind)Li affords the 1,2-dibromodigermenes, (Rind)BrGe=GeBr(Rind) (2) [Rind = Eind (b) and MPind (c)], as yellow to orange crystals. The ligand redistribution reaction between 1 and GeCl2·dioxane in toluene leads to the formation of the 1,2-dichlorodigermenes, (Rind)ClGe=GeCl(Rind) (3) [Rind = EMind (a), Eind (b), and MPind (c)]. The molecular structures of 1a, 1c, 2c, and 3c have been newly determined by X-ray crystallographic analysis. The 1,2-dihalodigermenes, (Rind)XGe=GeX(Rind) [X = Br (2) and Cl (3)], show a dimeric form with a Ge=Ge double bond in the solid state, but exist as a monomeric halogermylene, (Rind)XGe: [X = Br (4) and Cl (5)], in solution. The electronic properties of the Rind-based diarylgermylenes, dihalodigermenes, and halogermylenes have been experimentally and theoretically investigated.

Synthesis and characterization of the N-heterocyclic carbene ligand (NHC) precursors bearing long-alkyl chain substituent and the corresponding Ru(II)-carbene complexes for transfer hydrogenation catalysts

A new series of Ru(II)-NHC complexes [RuCl2(NHC)(p-cymene)] (4a-e) were obtained through a transmetallation reaction of the corresponding Ag(I)-NHC complexes with [RuCl2(p-cymene)]2 in dichloromethane (DCM) under Argon atmosphere. All new compounds were characterized by NMR spectroscopy, elemental analysis, FT-IR, MS, and the molecular structure of 4a was determined by X-ray crystallography. The complex of 4a adopts three-legged piano stool geometry with the facial planar p-cymene representing the “seat”, and the two chloro and one NHC ligands form the three “legs”. All complexes have been tested as catalysts for the transfer hydrogenation of aromatic ketones, showing moderate to high activity in this reaction.

Dispirooxindole-pyrrolothiazoles: Synthesis, anti-cancer activity, molecular docking and green chemistry metrics evaluation

A modest library of a set of dispirooxindole-pyrrolothiazole derivatives 5a–n has been synthesized through multicomponent technique employing 1,3-dipolar cycloaddition reaction of azomethine ylide with novel dipolarophiles, 2,6-di (arylmethylidene) -4-methylcyclohexanones 4a–n without any catalyst. The reaction provides simple and efficient access to synthetically useful and biologically important dispirooxindole-pyrrolothiazoles in high yield (86–98%) with high degree of stereo-, regio-, and chemo-selectivities. All the synthesized compounds were characterized using popular spectral methods like IR, 1H NMR, 13C NMR and 2D NMR techniques. Further, the molecular structure of 5a was confirmed by single crystal XRD. The synthesized compounds were subjected to cytotoxicity evaluation using K562-leukemia cell line. Compound 5 k has been found to be an effective compound of this class in targeting K562-leukemia cell with IC50 value of 13.28 ± 0.11 µg/ml. From the molecular docking data, it is realized that these compounds 5a–n showed a binding energy between -8.1 and -10.8 kcal/mol and thereby inhibit Tyrosine Kinases. Smaller E-factor (0.13), high atom-economy (89.74%), percentage yield (98.00%), reaction mass efficiency (88.43%), and carbon efficiency (96.97%) are successful achieved for compound 5j.

Comparison of chemical and biological properties of organometallic complexes containing 4- and 5-nitrothienyl groups

This study compares the nitro group position of thienyl imines bound to organometallic fragments, and the respective electrochemical and anti-parasitic properties. Ferrocenyl and cyrhetrenyl imines derived from 4-nitrothiophene (1a-3a) and 5-nitrothiophene (1b-3b) were synthesized and characterized by spectroscopic techniques. In addition, molecular structure of 1a, 2a and 3a were determined by X-ray crystallography.The reduction potential of the nitro group (E1/2), determined by cyclic voltammetry, shows that imines with a 5-nitrothiophene moiety exhibit lower E1/2 values (E1/2 = −0.56 to −0.78 V) than 4-nitro derivatives (E1/2 = −0.92 to −1.04 V), indicating that 5-nitro compounds better generate radical species.The 5-nitrothiophene derivatives (1b-3b) were more active against T. b. brucei (trypomastigotes) and T. cruzi (epimastigotes) than 4-nitrothiophene analogues (1a-3a). Enhanced trypanocidal properties in 5-nitrothiophenes may be due to NO2 group reduction being readily converted to their downstream, trypanocidal products. Based on the anti-parasitic activity and Selectivity Index determined for all derivatives, 1b emerged as an appropriated agent for treatment of trypanosomal infections. Additionally, evaluations of T. b. brucei susceptibility showed that compound 3b is a substrate for TbNTR1.Density Functional Theory (DFT) calculations were used as an approximation to rationalize the influence of nitro group positions on the heterocyclic ring regarding electrochemical behaviour and anti-parasitic activity.

Synthesis and characterization of 1,4-chalcogenesters bearing 5-membered heterocycles

Treatment of 1,4-(SeSiMe3)2-C6H4 (1) with two equiv of ClC(O)R (2) (a, R = 2-cC4H3O; b, R = 2-cC4H3S; c, R = 3-cC4H3S) produced the corresponding phenylene carboselenolates 1,4-(SeC(O)R)2-C6H4 (3a–c), while the reaction of 1,4-(SLi)2-C6H4 (4) with ClC(O)R (2) in a 1:2 molar ratio gave phenylene carbothiolates 1,4-(SC(O)R)2-C6H4 (5a–c). Compounds 3a–c and 5a–c were characterized by elemental analysis, NMR (1H, 13C{1H}, 77Se{1H}) and IR spectroscopy. The molecular structures of 3a–c and 5a–c in the solid state were determined by single-crystal X-ray structure analysis. The carbochalcogenato groups and the heteroatoms of the 5-membered rings are in an anti-arrangement with respect to each other. Cyclic voltammetry measurements show irreversible reduction processes for the 5-membered heterocyclic redox moiety in which reduction of these compounds lead to decomposition of the original compounds to unidentified species and show redox potentials between 1480 and 1580 mV for 3a-c and 1470−1490 mV for 5a-c, relative to the FcH/FcH+ redox couple. Also, thioester-functionalized systems 5a-c show significantly higher reduction potentials as compared to selenoesters 3a-c, reflecting the minor electron-donating effect of the sulfur atoms. The molecular electronic structures of the title compounds were additionally investigated by DFT calculations, revealing different degrees of HOMO-LUMO energy gaps within the series of 3a–c and 5a–c, due to a lowering in LUMO energy, depending on the nature of the heterocyclic ring. The calculations showed that the HOMO and LUMO are mainly located on the selenoester/thioester functionalized heterocyclic. The phase transition temperatures and enthalpies of the title compounds were detected by differential scanning calorimetry (DSC) analysis and the phases are confirmed by polarizing optical microscopy (POM). The mesomorphic investigation shows that compound 5a only exhibits enantiotropic smectic B (SmB) mesophase. In contrast, the other compounds do not show mesomorphic behavior, but simply changes from the solid crystalline state to the isotropic liquid. Biological activity of the compounds was evaluated using cytotoxicity assay on different cancer cell lines. Only compound 3c showed selective cytotoxic effect against MDA-231 and PC-3 cancer cell lines. The synthesis and characterization of phenylene carboselenolates 1,4-(SeC(O)R)2-C6H4 (3a–c) and phenylene carbothiolates 1,4-(SC(O)R)2-C6H4 (5a–c) were discussed. The solid state structures of the six compounds are reported. Electrochemical investigations show irreversible redox events. DFT calculations reveal different HOMO-LUMO gaps depending on the aryl substituent pattern. In addition, the liquid crystalline properties and the bioactivity test were carried out too.

CNC-pincer iron complexes containing a bis(N-heterocyclic carbene)Amido ligand: Synthesis and application to catalytic hydrogenation of alkenes

This work studied preparation and catalytic application of CNC-pincer Fe complexes containing a bis(NHC)amido ligand (NHC: N-heterocyclic carbene). Deprotonation of bis(3-isopropylimidazoliumyl)amine salt [(CNCiPr)H3]2+[I−]2 (1a) with lithium hexamethyldisilazide (LiHMDS) afforded the corresponding bis(NHC)amido-Li complex 2a. Treatment of in-situ generated 2a with FeI2(thf)2 gave a CNC-pincer Fe(II) iodide complex Fe(CNCiPr)I (3a) and a cationic homoleptic Fe(III) complex [Fe(CNCiPr)2]+I− (4a). Reaction of in-situ generated 2a with Fe[N(SiMe3)2]2 produced the corresponding amido complex Fe(CNCiPr)[N(SiMe3)2] (5a). Similarly, deprotonation of a less hindered methyl analogue [(CNCMe)H3]2+[I−]2 (1b) with LiHMDS followed by treatment of Fe[N(SiMe3)2]2 gave an amido complex Fe(CNCMe)[N(SiMe3)2] (5b). Molecular structures of 3a, 5a and 5b, which were confirmed by X-ray diffraction study, showed a distorted tetrahedral geometry. Complexes 3a and 5b were found to be active in hydrogenation of alkenes. Reaction mechanism was investigated by density functional theory (DFT) calculations.

New multifunctional heterobinuclear palladium (II) complexes based on organometallic dithiocarbazate ligands

In the research of new compounds with multifunctional applications, heterobinuclear palladium (II) complexes based on organometallic dithiocarbazates (DTCZs) have been isolated. The organometallic DTCZ ligands of the general formula [{(η5‐C5H4)‐CH=NNHC(S)SCH3}]MLn [MLn = Re (CO)3 (2a); Mn (CO)3 (2b); FeCp (2c)] were prepared by the reaction between formyl organometallic precursors (1a−c) with S‐methyldithiocarbazate. Subsequently, a two‐step reaction of 2a−c with: (i) K2[PdCl4] and (ii) PPh3 yielded heterobinuclear complexes [Pd{MLn(η5‐C5H4)‐CH=NNHC(S)SCH3}–(Cl)(PPh3)] [MLn = Re (CO)3 (3a); Mn (CO)3 (3b); FeCp (3c)]. All compounds were characterized by conventional spectroscopic techniques (infrared spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis). In addition, the molecular structures of 2a, 2c and 3c were determined by single‐crystal X‐ray diffraction. The new palladium (II) complexes (3a−c) were evaluated as antiproliferative agents against non‐small cell lung cancer cells (H1299 cells). Complexes 3a and 3b containing cyrhetrenyl‐ and cymantrenyl‐DTCZ ligands, respectively, were more active than their ferrocenyl analogue 3c. The activity was associated with the electron‐withdrawing properties of the (η5‐C5H4)M (CO)3 moieties and their better lipophilicity than that of the ferrocenyl analogue. In addition, we studied the capacity of metalloligands (2a−c) and palladium (II) complexes (3a−c) to remove methylene blue in water under UV–visible light irradiation. The results established that the complexes showed moderate efficiency and were less active than their corresponding free ligands.

Novel N-sulfonylphthalimides: Efficient synthesis, X-ray characterization, spectral investigations, POM analyses, DFT computations and antibacterial activity

Some novel N-sulfonylphthalimides were synthesized in good yields by condensation of anhydride phthalic with various sulfonamides by two different methods: conventional synthesis and immersion ultrasonic assisted method, in one step. These compounds were screened for their antibacterial activity against Escherichia coli, Staphylococcus aureus, Morganella morganii and Klebsiella pneumoniae.The bioinformatic POM analyses confirm the existence of a antifungal/or antiviral (Oδ-----Oδ-) pharmacophore sites. So it will benificial to test these molecules against other biotargets different of bacterial strains such as viruses, fungus and parasites.The molecular structure of 3a was obtained by X-ray diffraction on mono crystal. The crystal packing can be described as alternating layers in zigzag parallel to (100) plane along the c axis, which are connected together with C–H⋯O hydrogen bonds.

One-pot, catalyst-free synthesis of novel spiro[indole-3,4′-pyrano[2′,3′:4,5]pyrimido [2,1-b][1,3]benzothiazole] derivatives

The present report describes one-pot three-component condensation of isatins, malononitrile, and 2-hydroxy-4 H-pyrimido[2,1- b][1,3]benzothiazol-4-one in water–ethanol mixture at reflux to develop an efficient one-pot protocol for the synthesis of novel spiro[indole-3,4′-pyrano[2′,3′:4,5]pyrimido[2,1- b][1,3]benzothiazole] derivatives. The significant features of this protocol are short reaction times, avoidance of toxic catalysts, and provision of excellent yields, no column chromatographic purification, and use of ethanol-water as an environmentally benign solvent. The molecular structure of 4a has been supported by single-crystal X-ray diffraction.

Syntheses and structures of thiophosphorylatocavitands and their reactivity towards first-row transition metal halides

Two-step reactions of resorcin[4]arene (1) or methylresorcin[4]arene (2) with PPhCl2 and subsequent in situ oxidation with sulfur powder afforded a series of new thiophosphorylatocavitands 1a–1d or 2a–2d, respectively. Molecular structures of 1a⋅C3H6O, 1d⋅C3H6O⋅CH4O, 2a⋅2C2H6O⋅2H2O, and 2b⋅2C4H8O have been determined by X-ray diffraction analysis, which showed the C 4v stereoisomer with the four P = S bonds oriented towards the molecular cavity. The binding ability of thiophosphorylatocavitands 1a and 2b towards Cu(I), Mn(II), Co(II), Cu(II), and Zn(II) halides was studied by UV/vis absorption.