Synthesis, electrochemical and structural characterization of novel azacrown ether containing macrocyclic redox-active vic-dioxime ligand and its mononuclear transition metal complexes: Application of DEPT, HSQC, HMBC-NMR and cyclic voltammetry

This paper presents a new azacrown containing vic-dioxime; anti-N-(4-aminophenyl)aza-15-crown-5-glyoxime (LH₂), and its mononuclear nickel(II), copper(II), cobalt(II), cadmium(II) and zinc(II) complexes. The azacrown moieties appended at the periphery of the oxime provide solubility for the vic-dioxime ligand and complexes in common organic solvents. The mononuclear M(LH)₂ (M = Ni and Cu), M(LH)₂(H₂O)₂ (M = Co) and [M(LH)(H₂O)(Cl)] (M = Cd and Zn) complexes have been obtained with the metal:ligand ratios of 1:2 and 1:1. The structure of the ligand is confirmed by elemental analysis, Fourier transform infrared (FT-IR), ultraviolet-visible (UV-Vis), mass spectrometry (MS), one-dimensional (1D) ¹H, ¹³C NMR, distortionless enhancement by polarization transfer (DEPT) and two-dimensional (2D) heteronuclear single quantum coherence (HSQC) and heteronuclear multiple bond correlation (HMBC) techniques. The structures of the complexes are confirmed by elemental analyses, MS, UV-Vis, FT-IR and ¹H, ¹³C NMR techniques. Redox behaviors of the ligand and its complexes have been investigated by cyclic voltammetry at the glassy carbon electrode in 0.1 M TBATFB in DMSO. The antibacterial activity was studied against Staphylococcus aureus ATCC 29213, Streptococcus mutans RSHM 676, Enterococcus faecalis ATCC 29212, Lactobacillus acidophilus RSHM 06029, Escherichia coli ATCC 25922, Pseudomonasaeruginosa ATCC 27853. The antimicrobial test results indicate that all the complexes have low levels of antibacterial activity against both Gram negative and Gram positive bacterial species.     

Crystal structure of N,N,N',N'-tetrakis(methyldiphenylphosphino)-bis(2'-phenoxy)-3,6-dioxaoctane.

The title molecule, [C70H68N2O4P4], is a polydentate podand consisting of four etheral oxygens, two tertiary amine nitrogens and four diphenylphosphin groups. It crystallizes in the triclinic space group P1, and there is only one half a molecule in the asymmetric unit. The coordinations around the N and P atoms are pyramidal. The conformations about C20-C21, O2-C21 and O2-C22 are gauche, anti and anti, respectively.     

trans-2,4,4,6,8,8-Hexamorpholino-2,6-bis­(n-propyl­amino)cyclo-2λ5,4λ5,6λ5,8λ5-tetraphosph­aza­tetraene

The title compound, C₃₀H₆₄N₁₂O₆P₄, consists of a centrosymmetric chair-shaped cyclic tetrameric phosphazene ring with six bulky morpholino and two n-propyl­amino side groups. The two n-propyl­amino side groups are in trans positions. The bulky substituents mainly determine the eight-membered-ring conformation. The endocyclic N—P—N angles around the P atoms having different substituents are not the same as the P—N—P angles of the macrocyclic ring.     

Experimental, Theoretical and Biological Activity Study on the Acyl-Substituted Benzo-18-crown-6, Dibenzo-18-crown-6 and Dibenzo-24-crown-8

Hexadecanoyl, dihexadecanoyl, dioctadecaneoyl, di-10-undecenoyl, and dicis-9-octadecenoyl derivatives of benzo[18]crown-6, dibenzo[18]crown-6 and dibenzo[24]-8 were synthesized by the condensation of carboxylic acids (palmitic, stearic, oleic and undecenoic acid) with benzo and dibenzo crown ethers in the presence of zinc chloride. The extraction equilibrium constants of such macrocyclic ethers with long side chains were estimated using chloroform/water and dichloromethane/water membranes transfer of Na-PAR (4-(2-pyridylazo)-resorcinol mono sodium monohydrate) with UV–Vis spectroscopy. It was found that they were in the range of 10.88–11.71 in dichloromethane and 8.04–11.77 in chloroform. These results actually show that the Na+ binding effect of macrocyclic ethers depends on the type and the length of side chains. The geometrical properties of the molecules were studied employing semi-empirical calculations by simulated annealing technique. The frontier molecular orbital energies and dipole moments were also examined. The biological activity results showed that the synthesized crown ethers have no activity against the studied microorganisms.     

1,14‐Dioxa‐5,10‐di­aza‐2,3:12,13‐dibenzo­cyclo­octadeca‐2,12‐diene monohydrate

The title compound, C₂₂H₃₀N₂O₂·H₂O, is an 18‐membered di­aza‐crown ether ligand containing two ether O and two aza N atoms. In the macrocyclic ring, the mean N⋯O distance is 4.526 (4) Å. The macrocyclic inner‐hole size, estimated as twice the mean distance of the donor atoms from their centroid, is ∼2.29 Å.     

Generalized Pöschl-teller potential

From the point of view of the theory of differential equations, we present a four-parameter exactly solvable generalized Pöschl-Teller potential, related to the Jacobi polynomials, using the previously unconsidered equations.     

6‐Propylamino‐2,6‐propylepimino‐2,4,4,8,8‐pentakis(pyrrolidin‐1‐yl)‐1,3,5,7,2λ5,4λ5,6λ5,8λ5‐tetraazatetraphosphorocine

The title compound, C₂₆H₅₅N₁₁P₄, consists of a bicyclic phosphazene ring with five bulky pyrrolidino and one propyl­amino group, together with a second propyl­amino group bridging the two P atoms. The asymmetric unit contains two mol­ecules with very similar conformations. The bulky substituents are instrumental in determining the bicyclic P₄N₅ ring conformation. Each of the fused six‐membered N₃P₃ rings is in a sofa conformation. The P—N distances in the bridge are non‐equivalent and one of them is the longest P—N bond in the mol­ecule. The hybridization of the bridging N atom is pyramidal. The single and double P—N bonds cannot easily be distinguished, since they retain their phosphazenic character in the phosphazene macro‐rings.     

Phosphorus–nitrogen compounds part 33: in vitro cytotoxic and antimicrobial activities,DNA interactions,syntheses, and structural investigations of new mono(4-nitrobenzyl)spirocyclotriphosphazenes

The condensation reactions of hexachlorocyclotriphosphazene, N₃P₃Cl₆, with N-alkyl-N′-mono(4-nitrobenzyl)diamines (1–3), NO₂PhCH₂NH(CH₂) _n NHR₁ (R₁ = CH₃ or C₂H₅), led to the formation of the mono(4-nitrobenzyl)spirocyclotriphosphazenes (4–6). The tetra-pyrrolidino (4a–6a), piperidino (4b–6b), and 1,4-dioxa-8-azaspiro[4,5]decaphosphazenes (4c–6c) were prepared from(for) the reactions of partly substituted compounds (4, 5, and 6) with excess pyrrolidine, piperidine, and 1,4-dioxa-8-azaspiro[4,5]decane (DASD), respectively. The partly substituted geminal (4d and 5d) and cis-morpholino (6d) phosphazenes were isolated from the reactions of excess morpholine in boiling THF and o-xylene, but the expected fully substituted compounds were not obtained. The structures of all the phosphazene derivatives were determined by elemental analyses, MS, FTIR, ¹H, ¹³C{¹H}, ³¹P{¹H} NMR, HSQC, and HMBC techniques. The crystal structures of 4, 6, 4a, and 5a were verified by X-ray diffraction analysis. In addition, in vitro cytotoxic activities of fully substituted phosphazenes (4a–6c) against HeLa cervical cancer cell lines (ATCC CCL-2) and the compounds 4a and 4c against breast cancer cell lines (MDA-MB-231) and L929 fibroblast cells were evaluated, respectively. Apoptosis effect was determined by MDA-MB-231 cancer cell lines and fibroblast cells. The MIC values of the compounds were in the ranges of 9.8–19.5 µM. The compounds 6, 5a, 6a, 5b, and 6d have greater MIC activity against bacterial and yeast strain. The investigation of DNA binding with the phosphazenes was studied using plasmid DNA. The phosphazene derivatives inhibit the restriction endonuclease cleavage of plasmid DNA by BamHI and HindIII enzymes. BamHI and HindIII digestion results demonstrate that the compounds bind with G/G and A/A nucleotides.