Host selectivity behaviour of trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,2-diamine and trans-N,N′-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,2-diamine when presented with six-membered heterocyclic guest mixtures

Two compounds, trans-N,N′-bis(9-phenyl-9-xanthenyl)cyclohexane-1,2-diamine (1,2-DAX) and trans-N,N′-bis(9-phenyl-9-thioxanthenyl)cyclohexane-1,2-diamine (1,2-DAT), were assessed for their host ability in the presence of four heterocyclic guest species, namely pyridine (PYR), piperidine (PIP), morpholine (MOR) and dioxane (DIO). Each of these guests formed single solvent complexes with both host compounds. When 1,2-DAX and 1,2-DAT were recrystallized from various guest mixtures, it was shown that their selectivity orders were identical, DIO (46.6%)?>?MOR (23.0%)?>?PYR (18.9%)?>?PIP (11.5%) and DIO (85.9%)?>?MOR (23.7%)?>?PYR (8.9%)?>?PIP (8.5%), respectively, but that the thio host derivative possessed a significantly enhanced preference for DIO compared with its oxygen analogue. Additional experiments in order to investigate the various parameters at play in these complexation experiments involved single crystal diffraction experiments and thermal analyses.

     

An investigation of the complexation of host <Emphasis Type="Italic">N,N′</Emphasis>-bis(9-phenyl-9-thioxanthenyl)ethylenediamine with dihaloalkane guests

In this study, the formation of supramolecular inclusion complex of doxorubicin (DOX), a high loading and pH-dependent delivery of DOX on β-CD dendrimer was studied. β-cyclodextrin (β-CD) dendrimer having β-CD in both periphery and core was prepared with entrapment efficiency using click reaction. The encapsulation property of the β-CD-dendrimer was investigated by DOX as model drug. The chemical construction of β-CD-dendrimer was described by ¹H NMR, ¹³C NMR and FTIR and its inclusion complex construction was studied by FTIR, DSC, SEM, and DLS techniques. It was confirmed that β-CD dendrimer able to encapsulate DOX in solution; as a result, the designed complex revealed pH-dependent sustained release of DOX, in vitro. Also, the in vitro outcomes on T47D cells displayed that complexation of DOX with β-CD dendrimer involved an improvement of in vitro cytotoxicity and anticancer activity and this data appeared to be as a result of the developed solubility of the DOX.     

Compounds N,N′-bis(9-cyclohexyl-9-xanthenyl)ethylenediamine and its thio derivative,N,N′-bis(9-cyclohexyl-9-thioxanthenyl)ethylenediamine,as potential hosts in the presence of xylenes and ethylbenzene: Conformational analyses and molecular modelling considerations

Two novel crystalline compounds, N,N′-bis(9-cyclohexyl-9-xanthenyl)ethylenediamine (OED) and its thio derivative, N,N′-bis(9-cyclohexyl-9-thioxanthenyl)ethylenediamine (SED), were designed and synthesized in our laboratories, and assessed for their potential as host compounds for the four C8 aromatic compounds, namely o-, m- and p-xylene (o-Xy, m-Xy, p-Xy), and ethylbenzene (EB). Despite the only difference between the two compounds being the heteroatoms in their B rings, immense behaviour differences were noted: only OED displayed host behaviour in these conditions, clathrating all but m-Xy, while SED failed to form complexes with any of the four organic solvents. These observations prompted an investigation into the conformations of OED and SED through single crystal diffraction (SCXRD) analyses as well as computational studies with surprising results. SCXRD was also employed to analyse the three complexes that successfully formed with OED, and thermal analyses (TA) assisted in understanding the selectivity behaviour of OED when presented with mixed guests.     

Potential facile separation strategy for mixtures of 3- and 4-methylpyridine by employing N,N′-bis(9-phenyl-9-xanthenyl)ethylenediamine as an alternative host compound

In the present work, a plausible host candidate is provided for the separation of 3-methylpyridine (3MP) from 4-methylpyridine (4MP), isomers that are extremely difficult to separate by conventional means. Host compound N,N′-bis(9-phenyl-9-xanthenyl)ethylenediamine (H2), when recrystallized from an equimolar mixture of 3MP and 4MP, contained 91.6% 3MP, a significantly improved outcome compared with the alternate host compound N,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine (H1) which only enclathrated 70% of this isomer in the same experimental conditions. Single crystal diffraction and thermoanalytical experiments were conducted in order to investigate this preference for 3MP by considering both host?guest interactions and relative complex stabilities. Many of the guest components in 3(H2)·5(3MP)·0.268(O) experienced at least one other short contact measuring less than the sum of the van der Waals radii of the involved atoms, an observation that may explain the selectivity of H2 for this guest since this was not the case in complexes containing PYR and 4MP. Results from the thermal analyses were less informative.

     

Calorimetric study of the solubilization of ethylenediamine,N,N-dimethylaminoethylamine and N,N,N′,N′-tetramethylethylenediamine by reversed AOT micelles

Distribution constants and standard enthalpies of transfer of ethylenediamine (en), N,N-dimethylaminoethylamine (dmen) and N,N,N,N-tetramethylethylenediamine (tmen) partitioned between n-heptane and water containing reversed sodium bis(2-ethylhexyl) sulfosuccinate (AOT) micelles as a function of the molar concentration ratio R (R=[water]/[AOT]) were evaluated by a calorimetric method. The results show that en, dmen and tmen molecules, solubilized in the reversed micelles, are distributed between the micellar aqueous core and the micellar palisade layer. An analysis of the thermodynamic parameters of the partition process demonstrates the peculiar solvent properties of the water containing reversed AOT micelles.     

A highly selective magnetic solid-phase extraction method for preconcentration of Cd(II) using N,N′-bis(salicylidene)ethylenediamine in water and food samples

Research on Chemical Intermediates - In this work, a highly selective method is presented for the preconcentration of cadmium. The developed magnetic solid-phase extraction is based on the...     

Synthesis and structure of N,N′-bis(dihexylphosphorylmethyl)-1,4-diaminobutane

Russian Journal of General Chemistry - N,N′-Bis(dihexylphosphorylmethyl)-1,4-diaminobutane has been obtained via the Kabachnik–Fields reaction. Crystal structure of its salt with nitric...     

Ring Closure of N,N′:N,N′-bis(decamethylene)-1, 4-diamino-2,5-bis(10-cyanodecyloxy)benzene (IV)

Recently, β-chloro-α,β-unsaturated carbonyl compounds have become increasingly useful as intermediates in organic synthesis. For example, reactions involving a number of different cyclic β-chloro-α,β-unsaturated ketones with a variety of reagents (a malonate anion², the anion of the dithiolane derivative of ethyl glyoxalate³, zinc-silver couple in methanol⁴, dimethylsulfoxonium methylide^5,6) have produced a series of structurally diverse and potentially fruitful synthetic intermediates. The second-mentioned reagent has also been successfully reacted with a β-chloro-α,β-unsaturated ester³.     

Synthesis of 4,4′-bis(dichloroamino)- and 4,4′-bis(chloroamino)-3,3′-azofurazans,the first representatives of dichloroamino- and chloroaminofurazans

First representatives of dichloroamino- and chloroaminofurazans, viz., 4,4′-bis(dichloroamino)- and 4,4′-bis(chloroamino)-3,3′-azofurazans, were synthesized by the chlorination of 4,4′-diamino-3,3′-azofurazan with sodium hypochlorite in the CH₂Cl₂—H₂O mixture.     

Electrochemical synthesis and spectroscopy of the polymeric form of N,N′-bis(3-methoxysalicylidene)-1,3-propylenediamine

Electrochemical oxidation of N,N′-bis(3-methoxysalicylidene)-1,3-propylenediamine leads to the formation of a conducting polymer on the electrode surface. The diffusion coefficient and activation barrier of the charge transfer in the bulk of the polymer in an electrolyte medium were determined. The Schiff base and its polymeric form in the oxidized and reduced states were characterized by IR, X-ray photoelectron, and electronic absorption spectroscopy. Reversible changes in the polymer structure, accompanying its electrochemical oxidation-reduction, are substantiated.     

Stability constants of the complexes of Zn(II) and Mn(II) with N,N′-bis(2-hydroxyethyl) aminomethyl

The acid dissociation constants of N,N′-bis(2-hydroxyethyl) aminomethyl phosphonic acid (BHAMP) and the stability constants with Zn⁺⁺ and Mn⁺⁺ were determined at 25°C and at an ionic strength of 0.10 by means of potentiometric methods. The existence of a stable chelate species YM is illustrated. The equilibrium constants reported were calculated by the method developped by Schwartzenbach.     

Copper(II) and palladium(II) complexes of N,N′-bis(2-hydroxyethyl)stilbenediamine

A new 1,2-diamine ligand, N,N-bis(2-hydroxyethyl)stilbenediamine (L), has been prepared by reduction of the condensation product of benzaldehyde with 2-aminoethanol with Al amalgam. Mononuclear complexes of the [CuL(H₂O)]X₂ type where X=Cl^– or AcO^– with Cu^II and PdLCl₂ with palladium(II) have been prepared and characterized by elemental analysis and i.r., u.v.–vis. or ¹H-n.m.r. spectroscopy.     

Synthesis and properties of N,N′-bis(1,3-indanedion-2-yl)imidazolium betaine

A method for the synthesis of a new type of onium derivative of 1,3-indanedione — N,N-bis(1,3-indanedion-2-yl)imidazolium betaine — by anhydride condensation of N-(1,3-indanedion-2-yl)-N-carboxymethylimidazolium betaine with phthalic anhydride was developed. The new substance is an acid and forms stable salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 771–774, June, 1991.     

Synthesis,Crystal Structure and Spectroscopic Properties of N,N′-Diphenyl-N,N′-bis(2-fluorophenyl)-1,1′-biphenyl-4,4′-diamine

A fluorinated tetraphenylbenzidine derivative, N,N′-diphenyl-N,N′-bis(2-fluorophenyl)-1,1′-biphenyl-4,4′-diamine (C36H26F2N2, Mr = 524.59) was synthesized via the palladiumcatalyzed Buchwald-Hartwig reaction of N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine with 2-fluoroiodobenzene (yield: 75%) and structurally characterized. It crystallizes in monoclinic, space group P21/n with a = 9.820(7), b = 14.305(11), c = 10.233(8) , β = 108.973(9)o, V = 1359.3(18) 3, Z = 2, Dc = 1.282 g/cm3, μ(MoKα) = 0.084 mm-1, F(000) = 548, S = 1.018, the final R = 0.0439 and wR = 0.0928. It presents a linear centrosymmetric framework constituted by a linkage of biphenyl as a bridge and two fluorinated diphenylamine moieties. The UV-Vis absorption and fluorescence spectra of the title compound were also investigated. This compound emits intense blue fluorescence with a peak wavelength of 406 nm in film.     

Thermal behavior study of palladium(II) complexes containing the iminic ligand N,N′-bis(3,4-dimethoxybenzaldehyde) ethane-1,2-diamine

Journal of Thermal Analysis and Calorimetry - This study describes the synthesis, characterization and thermal behavior study of the Schiff base...     

Binuclear iron(III)-iron(III) complexes with the tetradentate Schiff base N,N′-bis(salicylidene)ethylenediamine and dicarboxylic acids or dithiooxamide as bridging ligands

Summary Complexes of the type [(Fe(salen))₂L]·xH₂O (L = glutarate, adipate, pimelate or suberate dianion, x = 0 or L = dithio oxamidate dianion, x = 2) have been prepared and studied by elemental analyses, i.r. and electronic spectra, and magnetic measurements. A dimeric structure with an octahedral arrangement of Fe^III (S = 5/2) is proposed. Some of the complexes have been characterized by temperature-dependent magnetic susceptibilities, but an antiferromagnetic exchange interaction was found only for [(Fe(salen))₂dta]·2H₂O (H₂dta = dithio-oxamide).     

Properties of N,N-Dimethyl-N′-(2-Hydroxybenzyl)ethylenediamine as a Ligand to Copper(II)

The acid-basic and complexing properties of N,N-dimethyl-N-(2-hydroxybenzyl)ethylenediamine (HL) in aqueous propan-2-ol were characterized by spectrophotometry, pH-metry, and mathematical simulation of equilibria in solutions (T = 25 ± 0.1°C, = 0.1 M KNO₃). Dimer H₂L₂ was found to predominate in solution at c _HL = 0.01 mol/l. Three protonated dimeric (H₃L₂ ⁺, H₄L₂ ²⁺, and H₅L₂ ³⁺), diprotonated monomeric (H₃L²⁺), and triprotonated tetrameric forms (H₇L₄ ³⁺) were detected in the system, depending on pH. At lower ligand concentrations (c _HL = 0.0015 mol/l), the solution contains both dimers and monomers of this compound. The higher dentate number of HL compared to 2-alkylaminomethylphenols allows it to form more number of both mono- and binuclear complexes ([Cu(HL)]²⁺, [Cu(HL)₂]²⁺, [CuL₂], [CuL₂OH]^–, [Cu₂(HL)₂]⁴⁺, and [Cu₂(HL)₂L₂]²⁺), making them more stable.     

Crystallographic and computational study of the structure of copper(II) 2,2′-bis(2-oxidobenzylideneamino)-4,4′-dimethyl-1,1′-biphenyl

The reaction of M(OAc)₂ with 2,2′-bis(2-hydroxybenzylideneamino)-4,4′-dimethyl-1,1′-biphenyl (H₂L1) allows the synthesis of 2,2′-bis(2-oxidobenzylideneamino)-4,4′-dimethyl-1,1′-biphenyl complexes of Cu(II) (CuL1), Co(II) (CoL1) and Ni(II) (NiL1) that were characterized by elemental analysis, FTIR spectroscopy and for CuL1 also by X-ray crystallography verifying a tetradentate binding mode of L1 via an (ONNO) motif of the two phenolic oxygen atoms and two azomethine nitrogen atoms. Recrystallization from a solvent mixture of dichloromethane and methanol promotes the formation of methanol adducts. Different binding modes of the methanol–complex were investigated using density functional theory calculations and binding energies, and thermodynamic data of the interaction are reported. The results show that the favored interaction occurs when the methanol molecule acts as a Lewis acid weakly binding via an O–H···O hydrogen bridge to a phenoxide moiety leading to an elongation of the respective M–O bond.

     

Structure and Spectroscopic Characteristics of N,N′-bis(2-Hydroxy-3-methoxyphenylmethylidene)2,6-pyridinediamine

The Schiff base N,N-bis(2-hydroxy-3-methoxyphenylmethylidene)-2,6-pyridinediamine has been synthesized and characterized in the solid state and in solution using X-ray analysis, IR, UV/Vis, and NMR spectroscopy. Crystal data: C₂₁H₁₉N₃O₄, M _r = 377.39, orthorhombic, space group Pnc2, a = 4.9288(8), b = 8.8873(19), c = 20.870(5) Å, V = 914.19(20) ų, Z = 2, R = 0.0387, R _w = 0.0530, 1845 independent reflections, 778 with I > 2(I). There are two intramolecular hydrogen bonds O—H-N between the hydroxyl and imino groups of 2.622(3) Å. The enolimine form is found in the solid state and is also the predominant tautomeric form in solution. Comparison of the title compound with the structurally related N,N-bis(salicylidene)-2,6-pyridinediamine and N,N-bis(salicylidene)-2,3-pyridinediamine is given.