Complexes of 2,2′,2″-Nitrilotriphenol. Part 2. Crystal and Molecular Structures of Three Boron Complexes

Crystal and molecular structures of a complex between B ( III ) and the tripod ligand 2,2′,2″-nitrilotriphenol as well as of its pyridine and quinuclidine adducts are presented. The 2,2′,2″-nitrilotriphenyl borate ( III ) molecule shows a strained, tricyclic chelate system with a central N–B donor-acceptor bond of 1.681(5) Å. In the adducts with pyridine ( IV ) and quinuclidine ( III -quin), this bond is broken, the N-atom inverts and is pushed out of the coordination sphere ( B–N _intern = 2.82 Å for Py and 2.85 Å for quin), and a new bond is formed between the boron atom and the external nucleophile ( B–N _extern = 1.631 Å for Py and 1.643 Å for quin).     

Synthesis and characterization of new copolymers of thiophene and vinylene: Poly(thienylenevinylene)s and poly(terthienylenevinylene)s with thioether side chains

Poly[3,4-bis(3-methylbutylthio)thienylenevinylene], poly[3,4-bis-(S)-(2-methylbutylthio)thienylenevinylene], poly[3′,4′-bis(3-methylbutylthio)-2,2′:5′,2″-terthienylene-5,5″-vinylene], and poly{3′,4′-bis-(S)-[2-methylbutylthio]-2,2′:5′,2″-terthienylene-5,5″-vinylene} have been synthesized. The synthesis starts from the thiophene monomers and trimers, which are formylated to give the corresponding dialdehydes. The dialdehydes are reductively polymerized using a McMurry coupling. The polymers are characterized by GPC, optical spectroscopy (FT-IR, UV-vis, circular dichroism spectroscopy and photoluminescence) and by proton and carbon NMR spectroscopy. The polymers are soluble in common organic solvents, such as THF, chloroform, toluene, benzene and 1,2-dichlorobenzene. The solvatochromism and thermochromism of the polymers in solution are investigated, while the optical activity of the polymers is used to investigate the supramolecular aggregation. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4629–4639, 1999     

Terpyridines as supramolecular initiators for living polymerization methods

Bis(5,5″-bis(bromomethyl)-2,2′:6′,2″-terpyridine), bis-4′-(4-bromomethylphenyl)-2,2′:6′,2″-terpyridine and 4-hydroxymethyl-5′,5″-dimethyl-2,2′:6′,2″-terpyridine metal complexes have been used as initiators for the living polymerization of 2-oxazolines and L-lactides. In both cases polymers with controlled molecular weights and narrow molecular weight distributions have been obtained. In-line diode array GPC measurements of iron(II) complexed poly(ethyloxazoline)s showed an unexpected absence of fragmentation. Viscosity experiments demonstrated the differences of the complexed and uncomplexed systems.     

Complexes of 2,2′,2″-Nitrilotriphenol. Part 1. A Study of Bimolecular Nucleophilic Substitution at the Boron Atom

The tetradentate ligand 2,2′,2″-nitrilotriphenol forms a boron complex III with an intramolecular, transannular N→B dative bond of 1.68 Å in a strained tricyclo[3.3.3.0]undecane chelating system. The complex reacts with nitrogen bases L, such as pyridine, quinuclidine and others, to form complexes III-L , in which the intramolecular B–N bond is replaced by one between B and the external nucleophile. In solution, this displacement reaction is reversible. It was studied by temperature-dependent NMR spectroscopy. The resulting reaction and activation parameters suggest that the reaction is a bimolecular nucleophilic substitution (S_N2).     

Kinetic study of 2‐propanol and benzyl alcohol oxidation by alkaline hexacyanoferrate(III) catalyzed by a terpyridyl ruthenium complex

The complex (Trpy)RuCl₃ (Trpy = 2,2′:6′,2″‐terpyridine) reacts with alkaline hexacyanoferrate(III) to form a terpyridyl ruthenium(IV)‐oxo complex that catalyzes the oxidation of 2‐propanol and benzyl alcohol by alkaline hexacyanoferrate(III). The reaction kinetics of this catalytic oxidation have been studied photometrically. The reaction rate shows a first‐order dependence on [RU(IV)], a zero‐order dependence on [hexacyanoferrate(III)], a fractional order in [substrate], and a fractional inverse order in [HO⁻]. The kinetic data suggest a reaction mechanism in which the catalytic species and its protonated form oxidize the uncoordinated alcohol in parallel slow steps. Isotope effects, substituent effects, and product studies suggest that both species oxidize alcohol through similar pericyclic processes. The reduced catalytic intermediates react rapidly with hexacyanoferrate(III) and hydroxide to reform the unprotonated catalytic species. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 760–770, 2000     

Syntheses and reactions of 2,2′-bisbenzimidazole systems

Nucleophilic reactions of two 2,2′-bisbenzimidazole systems, namely the bis(2H-benzimidazole-2-ylidene) 2 and the dispiro[2H-benzimidazole-2,1′-cyclohexane-4′,2″-2″H-benzimidazole] 3, as well as the syntheses of new 2,2′-bisbenzimidazoles are reported and their conversion into other heterocycles is described.     

New Heteroaromatic Complexing Agents and Luminescence of Their Europium(III) and Terbium(III) Chelates

Twelve heteroaromatic complexing agents 9a–I were synthesized with the purpose to develop suitable labels for time-resolved luminescence-based bioaffinity assays. The relative luminescence yields, excitation maxima, and emission decay constants of their europium(III) and terbium(III) chelates were determined. According to these results, 2,2′,2″,2?-[(2,2′-bipyridine-6,6′-diyl)bis(methylenenitrilo)]tetrakis (acetic acid) ( 9e ) and 2,2′,2″,2?-[(2,2′:6′,2″-terpyridine-6,6″-diyl)bis(methylenenitrilo)] tetrakis(acetic acid) ( 91 ) are the most promising agents.     

Synthesis,characterization, and evaluation of biological activities of new 4′‐substituted ruthenium (II) terpyridine complexes: Prospective anti‐inflammatory properties

The synthesis and characterization of Ru (II) terpyridine complexes derived from 4′ functionalized 2,2′:6′,2″‐terpyridine (tpy) ligands are reported. The heteroleptic complexes comprise the synthesized ligands 4′‐(2‐thienyl)‐ 2,2′:6′,2″‐terpyridine) or (4′‐(3,4‐dimethoxyphenyl)‐2,2′:6′,2″‐terpyridine and (dimethyl 5‐(pyrimidin‐5‐yl)isophthalate). The new complexes [Ru(4′‐(2‐thienyl)‐2,2′:6′,2″‐terpyridine)(5‐(pyrimidin‐5‐yl)‐isophthalic acid)Cl₂] ( 9 ), [Ru(4′‐(3,4‐dimethoxyphenyl)‐2,2′:6′,2″‐terpyridine)(5‐(pyrimidin‐5‐yl)‐isophthalic acid)Cl₂] ( 10 ), and [Ru(4′‐(2‐thienyl)‐2,2′:6′,2″‐terpyridine)(5‐(pyrimidin‐5‐yl)‐isophthalic acid)(NCS)₂] ( 11 ) were characterized by ¹H‐ and ¹³C‐NMR spectroscopy, C, H, N, and S elemental analysis, UPLC‐ESI‐MS, TGA, FT‐IR, and UV‐Vis spectroscopy. The biological activities of the synthesized ligands and their Ru (II) complexes as anti‐inflammatory, antimicrobial, and anticancer agents were evaluated. Furthermore, the toxicity of the synthesized compounds was studied and compared with the standard drugs, namely, diclofenac potassium and ibuprofen, using hemolysis assay. The results indicated that the ligands and the complex 9 possess superior anti‐inflammatory activities inhibiting albumin denaturation (89.88–100%) compared with the standard drugs (51.5–88.37%) at a concentration of 500 μg g^?1. These activities were related to the presence of the chelating N‐atoms in the ligands and the exchangeable chloro‐ groups in the complex. Moreover, the chloro‐ and thiophene groups in complex 9 produce a higher anticancer activity compared with its isothiocyanate derivative in the complex 11 and the 3,4‐dimethoxyphenyl moiety in complex 10 . Considering the toxicity results, the synthesized ligands are nontoxic or far less toxic compared with the standard drugs and the metal complexes. Therefore, these newly synthesized compounds are promising anti‐inflammatory agents in addition to their moderate unique broad antimicrobial activity.     

Synthesis and Ni(0)-catalyzed oligomerization of isomeric 4,4‴-dichloroquaterphenyls

4,4?-Dichloro-1,1′ : 2′,1″ : 2″,1?-quaterphenyl ( 9 ), 4,4?-dichloro-1,1′ : 3′,1″ : 3″,1?-quaterphenyl ( 10 ), and 4,4?-dichloro-1,1′ : 4′,1″ : 4″,1?-quaterphenyl ( 11 ) were synthesized by Pd (0) catalyzed cross-coupling reaction of 4-chlorobenzeneboronic acid with 2,2′-, 3,3′-, and 4,4′-bis (trifluoromethanesulfonyloxy)biphenyl respectively. 4,4?-Dichloro-1,1′ : 2′,1″ : 2″,1?-quaterphenyl ( 9 ) and 4,4?-dichloro-1,1′ : 3′,1″ : 3″,1?-quaterphenyl ( 10 ) were oligomerized by Ni(0) catalyzed homocoupling reaction to yield white and soluble oligophenylenes. © 1993 John Wiley & Sons, Inc.     

Complexes of Co(II), Ni(II), Cu(II), and Pd(II) with Sulfametrole-Cyclodiphosph(V)azane Derivatives

Novel [1,3-di-[N ₁ -4-methoxy-1,2,5-thiadiazole-3-yl-sulfanilamide(sulfametrole)]-2″4-bis-[1,3-dithiole-2-thione-4,5-dithiolate]-2′,4′-dichl-orocyclodiphosph(V)azane] (III) , was prepared and their coordinating behavior towards the metal ions Co(II), Ni(II), Cu(II), and Pd(II) was studied. The structures of the isolated products are proposed based on elemental analyses, IR, UV, ¹ H, and ³¹ P NMR, ESR, magnetic susceptibility, molar ratio, conductometric titration and electrical conductivity measurements. The prepared complexes showed high to moderate bactericidal activity compared with the ligand.     

Synthesis and supramolecular networks of mono- and dinuclear manganese chloride complexes with 2-(2,2′ : 6′,2″-terpyridin-4′-yl)phenol

2-(2,2′?:?6′,2″-Terpyridin-4′-yl)phenol has been prepared with an improved one-pot method. The reaction between the ligand and MnCl₂ in ethanol at ambient or hydrothermal conditions afforded dichlorido[2-(2,2′?:?6′,2″-terpyridin-4′-yl)phenol-κ³ N,N′,N″]manganese(II) and dichloridobis[µ-2-(2,2′?:?6′,2″-terpyridin-4′-yl)phenolate-κ³ N,N′,N″-κO]dimanganese(II), respectively. Face-to-face π–π stacking interactions between the pyridine rings play a crucial role in supramolecular networks of both complexes. Both complexes display weaker photoluminescence than the free ligand and the dinuclear complex luminescence was stronger than the mononuclear one.     

15N NMR coordination shifts in Pd(II), Pt(II), Au(III), Co(III), Rh(III), Ir(III), Pd(IV), and Pt(IV) complexes with pyridine, 2,2'-bipyridine, 1,10-phenanthroline, quinoline, isoquinoline, 2,2'-biquinoline, 2,2':6', 2'-terpyridine and their alkyl or aryl derivatives

The 15N NMR data for 105 complexes of Pd(II), Pt(II), Au(III), Co(III), Rh(III), Ir(III), Pd(IV), and Pt(IV) complexes with simple azines such as pyridine, 2,2'-bipyridine, 1,10-phenanthroline, quinoline, isoquinoline, 2,2'-biquinoline, 2,2':6', 2'-terpyridine and their alkyl or aryl derivatives have been reviewed. The 15N NMR coordination shifts, i.e. the differences between the 15N chemical shifts of the same nitrogen in the molecules of the complex and the ligand (Delta(15N) (coord) = delta(15N) (compl)--delta(15N) (lig)), have been related to some structural features of the reviewed coordination compounds, like the type of the central ion and the character of auxiliary ligands (mainly in trans position). These Delta(15N) (coord) parameters are negative, their absolute magnitudes (ca 30-150 ppm) generally increasing in the metal order Au(III) < Pd(II) < Pt(II) and Rh(III) < Co(III) < Pt(IV) < Ir(III), as well as with the enhanced trans influence of the other donor atoms (H, C < Cl < N).     

基于三联吡啶衍生物的Fe~(2+)/Fe~(3+)化学比色敏感器

合成和表征了一种新的化合物(E)-4-′(4-(2-(2-萘)乙烯基)苯基)-2,2′:6′,2″-三联吡啶L.用Fe2+或Fe3+来滴定时,L的溶液(三氯甲烷和乙醇的体积比为1∶20)颜色分别从无色变成洋红色和橙红色,相应的紫外可见吸收光谱都在374和574 nm出现特征吸收峰.此外,即使存在其它过量金属阳离子时,L对Fe2+或Fe3+离子仍然表现出很强的敏感性和选择性.另外,还研究了L对Fe2+或Fe3+离子及两者共同存在时的线性检测浓度范围和最低检测极限(LOD).     

Engineering with metallo-supramolecular polymers: linear coordination polymers and networks

Here we demonstrate the synthesis of telechelics with different spacer units and different numbers of metal-complexing units, like α-methoxy-ω-(2,2′:6′,2″-terpyrid-4′-yl)-poly(ethylenoxide)₇₈ ( 1 ), bis(2,2′:6′,2″-terpyrid-4′-yl) di(ethylene glycol) ( 2 ), bis(2,2′:6′,2″-terpyrid-4′-yl)-poly(ethylene oxide)₁₈₀ ( 3 ) and tris[(2,2′:6′,2″-terpyrid-4′-yl)-oligo (ethylenoxy-)_3.33]glycerin ( 4 ) utilizing 4-chloro-2,2′:6′,2″-terpyridine. The complexation behaviour of a variety of metal-salts towards the telechelics was studied and different supramolecular architectures were investigated, such as symmetric polymeric complexes and linear coordination polymers. Furthermore, attempts have been undertaken to prepare metallo-supramolecular cross-linked systems.     

Design and spectroscopic study of new ruthenium(II) complexes containing ligands derived from terpyridine and dipyrido[3,2‐a:2′,3′‐c]phenazine: {Ru(4′‐Rph‐tpy) [dppz(COOH)]Cl}PF6 with R = NO2, Br,Cl

A series of polypyridine ruthenium complexes of the general formula {Ru(Rph‐tpy)[dppz(COOH)]Cl} PF₆ with R = Br ( 1 ), Cl ( 2 ), NO₂ ( 3 ) where Rph‐tpy is 4′‐(4‐Rphenyl‐2,2′:6′,2″‐terpyridine and dppz(COOH) is dipyrido[3,2‐a:2′,3′‐c]phenazine‐2‐carboxylic acid were prepared and characterized. These complexes display intense metal‐to‐ligand charge‐transfer (MLCT) bands centered about 500 nm. The effect of pH on the absorption spectra of these complexes consisting of protonatable ligands has been investigated in water solution by spectrophotometric titration. The electrochemistry shows oxidation potentials for the Ru(II)–Ru(III) couple at +0.881 ( 1 ), +0.907 ( 2 ) and +0.447 V ( 3 ), respectively. Copyright © 2006 John Wiley & Sons, Ltd.     

Chromium(VI) oxide-mediated oxidation of polyalkyl-polypyridines to polypyridine-polycarboxylic acids with periodic acid

4,4′-Dicarboxy-2,2′-bipyridine was synthesized quantitatively by chromium(VI) oxide-mediated oxidation of 4,4′-dimethyl-2,2′-bipyridine or 4,4′-diethyl-2,2′-bipyridine with periodic acid as the terminal oxidant in sulfuric acid. 5,5′-Dicarboxy-2,2′-bipyridine and 6,6’-dicarboxy-2,2′-bipyridine were also synthesized by the method from the corresponding dimethyl bipyridines in excellent yields. 4,4′,4″-Tricarboxy-2,2′:6′,2″-terpyridine was obtained in 80% yield from 4,4′,4″-triethyl-2,2′:6′,2″-terpyridine, and 4,4′,4″,4′″-tetracarboxy-2,2′:6′,2″:6″,2′″-quaterpyridine was obtained in 72% yield from 4,4′,4″,4′″-tetraethyl-2,2′:6′,2″:6″,2′″-quaterpyridine by the same procedure.     

Foreword

Abstract

The crystal structure of the dinucleating 2,2′:6′,2″-terpyridine ligand 6′,6″-bis(2-pyridyl)-2,2′:4′,4″:2″,2?-quaterpyridine (btpy) has been determined and the two metal-binding tpy domains shown to be essentially planar and co-planar (P 1, a = 6.304(2), b = 8.208(2), c = 11.535(3) Å, α = 97.42(2), β = 104.25(2), γ = 96.23(2)°, Z = 1, d _c = 1.36 g cm^?3, 2214 unique observed reflections with I > 1.5[sgrave] (I), R = 0.0583); a methodology involving sequential reaction with non-labile and labile metal centres allows the specific assembly of heterometallic supramolecular oligomers such as [(Xtpy)Ru(btpy)M(btpy)Ru(Ytpy)]ⁿ⁺ (M = cobalt(II), cobalt(III) or iron).     

Four related diethyl [(arylamino)(4‐ethynylphenyl)methyl]phosphonates

Crystal structures are reported for four related diethyl [(arylamino)(4‐ethynylphenyl)lmethyl]phosphonate derivatives, namely diethyl [(4‐bromoanilino)(4‐ethynylphenyl)methyl]phosphonate, C₁₉H₂₁BrNO₃P, (I), diethyl ((4‐chloro‐2‐methylanilino){4‐[2‐(trimethylsilyl)ethynyl]phenyl}methyl)phosphonate, C₂₃H₃₁ClNO₃PSi, (II), diethyl ((4‐fluoroanilino){4‐[2‐(trimethylsilyl)ethynyl]phenyl}methyl)phosphonate, C₂₂H₂₉FNO₃PSi, (III), and diethyl [(4‐ethynylphenyl)(naphthalen‐2‐ylamino)methyl]phosphonate, C₂₃H₂₄NO₃P, (IV). The conformation of the anilinobenzyl group is very similar in all four compounds. The P—C bond has an approximately staggered conformation, with the aniline and ethynylphenyl groups in gauche positions with respect to the P=O double bond. The two six‐membered rings are almost perpendicular. The sums of the valence angles about the N atoms vary from 344 (2) to 351 (2)°. In the crystal structures, molecules of (I), (III) and (IV) are arranged as centrosymmetric or pseudocentrosymmetric dimers connected by two N—H...O=P hydrogen bonds. The molecules of (II) are arranged as centrosymmetric dimers connected by C_methyl—H...O=P hydrogen bonds. The N—H bond of (II) is not involved in hydrogen bonding.     

Diorganotin(IV) compounds derived from n‐methyl‐2,2′‐diphenolamine and 2,2′‐diphenolamine

The reaction of N‐methyl‐2,2′‐diphenolamine 1 and 2,2′‐diphenolamine 2 with some diorganotin(IV) oxides [R1/2SnO: R¹ = Me, n‐Bu, t‐Bu and Ph] led to the syntheses of diorgano[N‐methyl‐2,2′‐diphenolato‐O,O′,N]tin (IV) 3–6 and diorgano[2,2′‐diphenolato‐O,O′,N]tin (IV) 7–9 . All compounds (except 7 ) studied in this work were characterized by ¹H, ¹³C, ¹¹⁹Sn NMR, infrared, and mass spectroscopy. Their ¹¹⁹Sn NMR data show that the tin atom is tetracoordinated in CDCl₃ but penta and hexacoordinated in DMSO‐d₆. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 133–139, 1999     

Electrochemical oxidation of substituted pyrroles. III. Anodic oxidation of 2,5-diphenyl-3-acetylpyrrole

The electrochemical oxidation of 2,5-diphenyl-3-acetylpyrrole (I) is described. The cyclic derivative 1,6a-dihydro-2,5,6a-triphenyl-3,4-diacetylbenzo[g]pyrrolo[3,2-e]indole (II) was obtained in very good yield. However, when water was present in the reaction medium, a different derivative, 4-acetyl-2-hydroxy-2,5-diphenyl-3-(4′-acetyl-2′,5′-diphenyl-3′-yl)-2H-pyrrole (III) , was obtained as the main product. 2,2′,5,5′-Tetraphenyl-4,4′-diacetyl-3,3′-dipyrryl (IV) , a potentially useful intermediate for the synthesis of condensed pyrroles, was synthesized by zinc reduction of III.