Polycyclic Phosphorus-Containing Oxaboracyclanes

Abstract

The olygomers consisting of regularly repeating heterocyclic fragments were synthesized by the reaction of polycondensation of the ether of p-phenylenediboric acid and tetraoxymethyloldphosphioes obtained from the different diphosphines and aldehydes. The compounds with endocyclic phosphorus atom (I) were obtained in case of using the aliphatic aldehydes, and the compounds with exocyclic phosphoruscontaining group (II) were obtained when using the hydroxyaldehydes.     

A selective chemosensor for detection of Ag(I) and Cu(I) based on an acenaphthoquinone derivative and its complexes

A new Schiff base, acenaphthoquinone bis(diphenylmethlenehydrazone) (L), was synthesized and employed as a chemosensor for detecting Ag(I) and Cu(I). Experimental results showed that the chemosensor exhibited high selectivity and sensitivity. The sensitivity of the chemosensor for Ag(I) or Cu(I) was not affected by other metal ions, such as Ni(II), Nd(III), Zn(II), Fe(III), Cu(II), Na(I), La(III), K(I), and Co(II). Complexes 1 and 2 were synthesized by coordination of L with Ag(I) and Cu(I), respectively. The crystal structures of 1 and 2 were determined by single-crystal X-ray diffraction. They had the same space group P2₁/c. Based on theoretical calculation, mechanism of the chemosensor detecting Ag(I) and Cu(I) was suggested.     

New Cyclopendant Organophosphorus Ligands

Abstract

New cyclopendant orgsnophosphorus neutral ligands were synthesized from cyclic polyamines. N,N′,N″-Tris-(diphenylphosphorylmethyl) 1,4,7-triazacyclononane(I) was obtained by the reaction of triazacyclononane with diphenylphosphine oxide and formaldehyde. Interaction of 1,4,7,10-tetraazacyclododecane with diphenylvinyl-phosphine oxide N,N′,N″,N?-tetra(β-diphenylphosphorylethyl)-1,4,7,10-tetraazacyclododecane(II) was obtained.     

Study of Tautomerism in Some β-Keto Phosphoryl Prototropic Pentad Systems

Abstract

By the reaction of phosphoryl substituted acylmethylenetriphe-nylphosphoranes (I, II) with hydrogen halides prototropic pentad tautomeric systems (III, IV) have been obtained.     

NOTE: SYNTHESIS OF Cu(II) AND Zn(II) COMPLEXES WITH SCHIFF BASE DERIVATIVES OF 2-ACETYLPYRROLE

Abstract

Bis chelate complexes of Cu(II) and Zn(II) were synthesized with methylamine and ethylamine Schiff base derivatiies of 2-acetylpyrrole. Stable complexes were obtained, with the exception of the Cu(II) ethylamine adduct. which slowly hydrolyzed in air to yield a mixed ligand product containing one ethylamine Schiff base and one 2-acetylpyrrole per metal centre. The instability of the bis Cu(II) ethylamine Schiff base complex with respect to stable Cu(II) methylamine and Zn(1I) ethylamine complexes is discussed.     

From mononuclear to polynuclear: copper and zinc complexes obtained from polypyridylamine ligands related to tris(2-pyridylmethyl)-amine (tmpa)

Abstract

Copper(I)/(II) complexes and a zinc compound with polypyridylamine ligands (related to the tripodal ligand tris(2-pyridylmethyl)amine, tmpa) were synthesized. Crystallographic characterization was possible for most of the complexes obtained. The different structures of the complexes allowed some insight into the basic understanding of the design of coordination polymers. Depending on ligand, solvent or anion, either mononuclear, dinuclear or polynuclear complexes were obtained.     

An x-ray diffraction study of the reaction products of copper(II) chloride with N<Superscript>1</Superscript>,N<Superscript>2</Superscript>-bis(5-methylpyridin-2-yl)oxalamide

Polymeric complexes of [Cu₂Cl₂L₂]_∞ copper(I) chloride (1) (L = N¹,N²-bis(5-methylpyridin-2-yl)-oxalamide)) and {[Cu₂(C₂O₄)Cl₂L](L)·2H₂O}_∞ copper(II) chloride (2) are obtained. The complexes are studied by powder and single crystal XRD. It is found that during the reaction of L with copper(II) chloride in the formation of complex 1 copper(II) is reduced to copper(I), while the formation of complex 2 is accompanied by the hydrolysis of the ligand.     

Manganese(II) and silver(Ι) complexes based on the V-shaped ligand,bis(2-benzimidazolylmethyl)amine: synthesis,crystal structures,DNA-binding properties,and antioxidant activities

Two Mn(II) and Ag(I) complexes, [Mn(IDB)₂](pic)₂ (pic?=?picrate) (1) and [Ag₂(IDB)₂](pic)₂ (2) (IDB?=?bis(2-benzimidazolylmethyl)amine), have been synthesized and characterized by elemental analysis, IR, UV–vis spectral measurements, and X-ray single-crystal diffraction. Single-crystal X-ray diffraction revealed that Mn(II) is six-coordinate by six nitrogens from two IDB as a distorted octahedron, and the Ag(I) complex revealed two Ag(I) ions bonded to two IDB ligands through six nitrogens, resulting in an asymmetric binuclear structure. The complexes can bind to DNA through an intercalative mode, and the affinity for DNA is stronger for the Mn(II) complex than the Ag(I) complex; the Mn(II) complex exhibits excellent antioxidative activity.     

Coordination compounds of 4,5,6,7-tetrahydro-1H-indazole with Cu(II), Co(II) and Ag(I): structural,antimicrobial, antioxidant and enzyme inhibition studies

Coordination behavior of 4,5,6,7-tetrahydro-1H-indazole (H-Ind) with Cu(II), Co(II), and Ag(I) was studied. The ligand affords complexes bearing different geometries depending upon the metal and anion present in the starting salts. Five compounds with different structural perspectives, trans-[CuCl₂(H-Ind)₄] (1), trans-[CuBr₂(H-Ind)₄] (2), trans-[Cu(CH₃COO)₂(H-Ind)₂] (3), trans-[CoCl₂(H-Ind)₄] (4), and [Ag(H-Ind)₂]NO₃ (5), were obtained. The ligand adopts tetrahydro-1H-indazole isomeric form in Cu(II) and Co(II) complexes and with Ag(I) ion the same ligand adopts tetrahydro-2H-indazole form. In the case of sterically demanding acetate counter ion in contrast to Cl or Br, the Cu(II) ion accepts two equivalents of the ligand and four-coordinated square planar complex was obtained. With AgNO₃, the expected complex was obtained. The yield of reactions was >80% and all complexes were obtained as crystalline material from the reaction mixtures. Their structures were determined by X-ray diffraction and all complexes were tested for antibacterial (Enterobacter sakazkii, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniea), antifungal (Aspergillus flavus, Aspergillus fumegatus, Aspergillus nigar, Fusarium oxysporium), and antioxidant (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH)) activities. The same were also tested as inhibitors against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) .     

Direct Resolution of Secondary Tert-Butylphenylphosphine Oxide

Abstract

Secondary phosphine oxides constitute an important class of organophosphorus compounds and are higly useful as versatile phosphinoylating agents and as ligands ^[1,2] They are however not readily available in the optically active form.^[3–5] We wish to demonstrate that P-chiral secondary teri-butylphenylphosphine oxide (I) can be promptly resolved into enantiomers by means of its diastereoisomeric complexes with L-O,O-dibenzoyltanaric acid (L-DBTA) Dissolution of equimolar amounts of racemic I and L-DBTA in the 4 I benzene acetone mixture yields crystalline II complex containing exclusively the R-enantiomer of the starting phosphine oxide The complexed S-enantiomer is obtained from the mother liquor by crystallization from benzene The enantiomers of I are freed from their L-DBTA complexes by simple washing with aqueous NaOH Both enantiomers of 1 of very high optical purity are thus obtained from a single batch These enantiomers have subsequently been tested for their configurational stability in selected synthetic applications.     

Ag(I) and Zn(II) isonicotinate complexes: design,characterization, antimicrobial effect,and CT-DNA binding studies

Trinuclear Ag(I) (1) and dinuclear and mononuclear Zn(II) isonicotinate (2 and 3) complexes were prepared and characterized by X-ray crystallography, elemental analysis, IR spectroscopy, and thermal analysis. Single-crystal analysis of the Ag(I) complex reveals two different monodentate carboxylate coordination modes, protonated and deprotonated, respectively. IR spectra showed correlations between isonicotinate coordination modes and Δ(ν_as???ν_s)_IR values. In addition, the hydrogen bonds significantly influence a position of carboxylate absorption bands. Moreover, IC₅₀ and MIC data for bacteria, yeasts, and filamentous fungi were determined and the binding of Ag(I) and Zn(II) complexes to calf thymus DNA was investigated using electronic absorption, fluorescence, and CD measurements. Biological tests showed that the Ag(I) complex is more active than commercially used Ag(I) sulfadiazine against Escherichia coli. The fluorescence spectral results indicate that the complexes can bind to DNA through an intercalative mode. The Stern–Volmer quenching constants for investigated complexes obtained from the linear quenching plot are in the range of 1.67 × 10⁴–3.42 × 10⁴ M^?1.     

The Novel Phosphadiazacalixcrown Compounds

Abstract

A new series of calixcrown compounds (11) containing some VA group elements (N, P) was synthesized. 1.3-bis-(aminoethoxy) calix[4]arene (I) was used as starting platform for the preparation of calixcrown compounds. Reaction of (I) with bis(a-hydroxyalky1)phenylphosphines in toluene lead to phosphadiazacalixcrown compounds (11). All obtained receptors are hydrolytic stable and are not oxidized by air. A more convenient synthesis of (II) involves treatment of (I) with 2.5-diphenyl-1.3.2.5-dioxaboraphosphorinanes (III) which are stable on air unlike bis-(a-hydroxyalkyl) phenylphosphines. Structure of obtained macrocycles was established by ¹H and ³¹P NMR spectroscopy.     

Preparation of copper sulphide clusters in organic-inorganic composites of Langmuir-Blodgett films of amphiphilic Schiff bases

Copper sulphide clusters were prepared in Langmuir-Blodgett films of copper complexes of amphiphilic Schiff bases-3,4-dimethoxy-N-benzylidene hexadeylamine (I) and 3,4-dimethoxy-N-benzylidene-4’-(hexadecylamino) benzylamine (II) The clusters obtained were analysed using UV-Vis spectroscopy and optical microscopy. Brewster angle microscopic studies on monolayers ofI andII at air/water interface showed formation of needle-like domains which seem to cluster faster inI than inII. Atomic force microscopy (AFM) studies also showed fairly uniform sized clusters inII whereas in the case ofI they seem to show varying sizes. From the results it is concluded that π-elongation in the polar head groups leads to controlled cluster sizes in compoundII as compared to those in compoundI.     

Synthesis of 5-Carbonyl-1,3-dihydro- 1,3-dioxo-2H-isoindole-2-propanoic Acid Integrin Antagonists

Abstract

The 5-carboxy-1,3-dihydro-1,3-dioxo-2H-isoindole-2-propanoic acid benzyl ester (I), obtained from condensation of 1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylic acid with β-alanine benzyl ester p-toluenesulfonate, reacted with an appropriate amine (II) to afford the corresponding amide (IIIa–e), which then hydrogenolyzed by 5% palladium-on-carbon to give target compounds (IVa–e).     

Synthesis and Study of Spatial Structure 3,7-Bis(Dimethylamino)-5,10-Dihydrodibenzo-[b,e]- Phosphorines by NMR

Abstract

The phosphorines (VIII-XI) were obtained in the reaction 3,3-bis(dimethylamino)triphenylphosphine (I) and bis(3-dimethylaminophenyl) pentafluorophenylphosphorine (II) with benzaldehyde (III) and its 4-methoxy (IV), 4-dimethylamino (V), 2-fluro (VI), pentafluoro (VII) derivatives according to the scheme (1).     

Ferromagnetic copper(II)–copper(II) interaction in a single chlorido and dicyanamido bridged mixed–valence copper(I/II) 2-D polymer generated by in situ partial reduction of copper(II)

A mixed-valence 2-D Cu(I/II) complex, [{Cu(II)(dmen)(μ-Cl)(μ_1,5-dca)}{Cu(I)(μ_1,5-dca)}]_n (1) (dmen = N,N-dimethylethylenediamine, dca = dicyanamide = [N(CN)₂]^?), has been synthesized by in situ partial reduction of Cu(II) to Cu(I) using benzoin (2-hydroxy-1,2-di(phenyl)ethanone) as reductant. Complex 1 was characterized by spectroscopic techniques, single crystal X-ray diffraction, and low temperature magnetic measurements. Structural investigation reveals that 1 represents a mixed-valence 2-D coordination polymer formed by parallel 1-D [Cu(II)(dmen)(Cl)Cu(I)(μ_1,5-dca)₂]_n chains running along the b axis, where chloride bridges Cu(II) ions of adjacent polymers through long connections (2.8401(1) Å) to form a 2-D network. The metal centers have two different geometrical environments (distorted square pyramidal and distorted trigonal planar geometries for Cu(II) and Cu(I), respectively). The Cu(II) ions in [Cu(II)(dmen)(μ-Cl)(dca)]_n are interconnected through single chloride bridges while within the [Cu(I)(μ_1,5-dca)]_n units, the dca connects adjacent Cu(I) ions through μ_1,5-dca bridges. Magnetic susceptibility measurements reveal weak ferromagnetic interactions (J = +0.3 cm^?1) within the chlorido-bridged Cu(II) regular chain present in 1. Simultaneous presence of μ_1,5-dca and single chlorido bridges with ferromagnetic coupling is believed to be unique in mixed-valence Cu(I)/Cu(II) complexes.     

The Decomposition of Transition Metal Tetrafluoroborates by some strong Base Ligands

Abstract

Some transition metal complexes of triethylene-diamine (TED, I) and quinuclidine (Q, II) have been reported.^1–5 Recently we treated I and II with metal bistetrafluoroborates (M=Co²⁺, Ni²⁺, and Cu²⁺) which have not been studied yet, and postulated that pure coordination complexes might be obtained. However, evidence for the existence of 1:1 adducts such as C₆H₁₂N₂:BF₃ (III) and C₇H₁₃N:BF₂ (IV) in treatment of I and II with metal bistetrafluoroborates has now been found. We wish to describe our results concerning formation of these two new 1:1 adducts in this letter.     

Synthesis and investigation of antibacterial activities and carbonic anhydrase and acetyl cholinesterase inhibition profiles of novel 4,5-dihydropyrazol and pyrazolyl-thiazole derivatives containing methanoisoindol-1,3-dion unit

Novel 4,5-dihydropyrazole derivatives (3a–i), 3-(4-((3aR,4S,7R,7aS)-1,3-dioxo-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindol-2(3H)-yl)phenyl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbothio amide, were obtained by the addition of thiosemicarbazide (2) to the chalcones (1a–i). The addition–cyclization of 2,4′-dibromoacetophenone (4) to pyrazole derivatives (3a–i) gave the new pyrazolyl-thiazole derivatives (5a–i), (3aR,4S,7R,7aS)-2-(4-(1-(4-(4-bromophenyl)thiazol-2-yl)-5-phenyl-4,5-dihydro-1H-pyrazol-3-yl)phenyl)-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindole-1,3(2H)-dione. Antibacterial and acetylcholinesterase (AChE) enzyme and human carbonic anhydrase (hCA) I, and II isoform inhibitory activities of the compounds 3a–i and 5a–i were investigated. Some of the compounds showed promising antibacterial activity. In addition, the hCA II and I were effectively inhibited by the lately synthesized derivatives, with K_i values in the range of 18.90?±?2.37 ?58.25?±?13.62?nM for hCA II and 5.72?±?0.98 ?37.67?±?5.54?nM for hCA I. Also, the K_i parameters of these compounds for AChE were obtained in the range of 25.47?±?11.11???255.74?±?82.20?nM. Also, acetazolamide, clinical molecule, was used as a CA standard inhibitor that showed K_i value of 70.55?±?12.30?nM against hCA II, and 67.17?±?9.1?nM against hCA I, and tacrine inhibited AChE showed K_i value of 263.67?±?91.95.     

Bis(diphenylphosphino)Alkane / Co(II)/Tetrahydroborate and Cyanotrihydroborate Reactions: Formation of Unusual Bis(diphenylphosphino)methane Complexes and the Influence of Carbon Monoxide

Abstract

Reactions between Co(II), bis(diphenylphosphino)methane (dppm) and either NaBH₄ or NaBH₃CN have been studied. They follow pathways which are in marked contrast to those followed by Ph₂P(CH₂)nPPh₂ (n=2?6) in the presence of NaBH₄ in which the final product is normally CoH(phosphine)₂ although binuclear BH₄-bridged complexes may sometimes be obtained. The products obtained with dppm are Co₂X₃(dppm)₂ (X=Cl,Br) (I), CoCl(dppm)₃ (II), {CoHX(dppm)₂}Y (X=Cl, Br, I, BH₃CN; Y=Cl,BH₃CN,BPh₄,Clo₄) (III), and Co₂H₂(dppm)₃ (IV). While a binuclear A-frame structure can be proposed for the Co(I)-Co(II) species (I), crystal twinning has so far prevented an X-ray determination. However, X-ray studies on (II) and (IV) have shown that (II) contains tetrahedral Co(I) to which one chloro and three monodentate dppm ligands are attracted while (IV) is a binuclear species containing bridging dppm ligands and two terminal hydrides. The compounds (III) are octahedral Co(III) complexes. Possible mechanisms for the formation of these in strongly reducing environments will be discussed.     

SELENOETHER COMPLEXES OF COPPER(II) ‐ SYNTHESIS,SPECTROSCOPY AND STRUCTURES

Abstract

The red-brown copper(II) diselenoether complexes, [Cu (L-L)₂][BF₄]₂ (L-L = MeSeCH₂CH₂SeMe, MeSeCH₂CH₂CH₂SeMe or PhSeCH₂CH₂SePh) have been prepared from copper(II) fluoroborate and the ligands in anhydrous dichloromethane. Some new dithioether analogues are also described. The reaction of MeSeCH₂CH₂SeMe and copper(II) fluoroborate in ethanol led to an unstable dark green substance which appeared to contain both copper(I) and copper(II) and was formulated [Cu(MeSeCH₂CH₂SeMe)₂] [BF₄]_x. The complexes were characterised by analysis, UV-visible and e.p.r. spectroscopy, and magnetic measurements, and cyclic voltammetry has been used to probe the Cu (II)/Cu(I) redox couples. The complexes are too unstable in solution to obtain crystals for an X-ray study, but structural data has been obtained for both the Cu(II) and Cu(I) complexes by copper K-edge EXAFS studies. Ditelluroethers reduce copper(II) salts to copper(I) complexes.