Vibrational spectra and molecular configuration of 2,2′-diphenyl ethyl alcohol and 2,2′-diphenyl ethylamine

The Raman and IR spectra of 2,2′-diphenyl ethyl alcohol and 2,2′-diphenyl ethylamine have been analyzed assuming the phenyl rings vibrate independently. Complete vibrational assignment show that some ring modes for both the molecules are found to appear in pairs. Possible orientation of the two rings with respect to the tetragonally hybridized carbon atom has been discussed. Two probable cases of Fermi resonance have been observed. The general nature of the ring modes to exhibit a pair of frequencies in some diphenyl-type molecules has been described.     

Homo- and heterodinuclear 2,2′-bipyrimidine-bridged complexes

[M(hfacac)₂(bpym)] complexes, where M = Co^II, Ni^II or Zn^II, hfacac = hexafluoroacetylacetonate and bpym = 2,2bipyrimidine; and [Cl₂M(bpym)M(hfacac)₂] complexes, where M = Co^II, Ni^II Mn^II or ZnII M = Ni^II; M = NiII or Zn^II and M = Zn^II; M = Ni^II and M = Co^II have been prepared and characterized by chemical analysis, conductance measurements, IR and electronic spectroscopies and magnetic susceptibility measurements (4.2–292K range). The dinuclear NiII–Ni^II, Co^II–Ni^II and Mn^II–Ni^II complexes are antiferromagnetic, with an intramolecular exchange parameter, J, of –2.3–8.9cm–1. Co^II and Mn^II are in a high spin state. The low temperature effect observed in monomers and in Ni^II–Zn^II dimers is considered a consequence of either an intermolecular antiferromagnetic interaction or the zero-field splitting in NiII.     

Synthesis and characterization of complexes of the first transition series cations with 2,2′-biimidazole and 2,2′-biimidazolate

Mononuclear [M(hfacac)₂(H₂biim)] complexes, where M = Mn^II, Fe^II, Co^II, Ni^II, Cu^II or Zn^II, hfacac = hexafluoroacetylacetonate, H₂biim = 2,2-biimidazole; dinuclear K₂[M₂(acac)₄(-biim)] (M = Cu^II or Zn^II) and tetranuclear K₂[M₄(acac)₈( ₄-biim)] (M = Co^II or Ni^II) complexes have been prepared and characterized by chemical analysis, conductance measurements, i.r., electronic and e.p.r. spectroscopies and by magnetic susceptibility measurements (in the 2–300 K range). Mn^II, Fe^II and Co^II are in a high spin state. The e.p.r. spectra of Cu^II and Mn^II compounds have been recorded.     

Preparation and Characterization of 2,2′-Dipicolyl Diselenide and Their Derivatives

Lithium 2-picolylselenolate/tellurolate is obtained by reacting lithiated 2-picoline with elemental selenium/tellurium which upon aerial oxidation gives 2,2'-dipicolyl diselenide in case of selenium while 1,2-bis(2-pyridyl)ethane in case of tellurium. Condensation of 2-picolylselenolate anion with a variety of electrophiles provides a facile synthesis of 2-picolylalkyl selenides in good to excellent yields. Quenching of lithiated 2-picoline with 2,2'-dipyridyl diselenide gives mixed 2-picolylseleno pyridine in low yield. All the compounds prepared are new and have been characterized by elemental analysis, 1 H NMR, 13 C NMR and mass spectral studies.     

Synthesis and structure of 2,2′-diaminodiphenylditelluride bis-imines

Bis-imines of 2,2′-diaminodiphenylditelluride and 2-tosylamino (9a) and 2-hydroxybenzaldehyde (9b) were prepared and studied by X-ray diffraction, heteronuclear (¹H, ¹³C, ¹⁵N, and ¹²⁵Te) magnetic resonance, and quantum chemical calculations (Pbe1pbe/DGDZVP). According to the X-ray diffraction data, compound 9b in the crystal phase has nonsymmetrical structure: one of the tellurium atoms forms hypervalent bonding with the adjacent oxygen atom, while the second one is not involved in such interaction. The NMR study showed the symmetric molecular structure of imines 9a,b in DMSO-d₆ with the tellurium atoms interacting hypervalently with the C=N nitrogen atoms.     

Supramolecular Assemblies of (±-2,2''''-Dihydroxy-1,1''''-binaphthyl with 2,2''''-Bipyridine and Naphthodiazine

Introduction Optically active 1,1'-bi-2-naphthol (BINOL) and its derivatives have been widely used as chiral ligands of catalysts for asymmetric reactions and effective host compounds for the isolation or optical resolution of a wide range of organic guest molecules through the for-mation of crystalline inclusion complexes.1,2 The wide-ranging and important applications of these com-pounds in organic synthesis have stimulated great inter-est in developing efficient methods for their prepara-…     

Heat Capacities and Thermodynamic Properties of 3-（2,2-Dichloroethenyl）-2,2-dimethylcyclopropanecarboxylic Acid

The heat capacities of 3 - (2,2-dichloroethenyl) -2,2-dimethylcyclopropanecarboxylic acid ( a racemic mixture,molar ratio of cis-/trans-structure is 35/65) in a temperature range from 78 to 389 K were measured with a precise automatic adiabatic calorimeter. The sample was prepared with a purity of 98.75% ( molar fraction). A solid-liquid fusion phase transition was observed in the experimental temperature range. The melting point, Tm, enthalpy and entropy of fusion, △fusHm, △fusSm, of the acid were determined to be ( 331.48 ± 0.03 ) K, ( 16. 321 ± 0.031 ) kJ/mol,and (49.24 ± 0.19) J/( K·mol), respectively. The thermodynamic functions of the sample, HT - H298.15, ST -S298.15 and GT - G298.15, were reported at a temperature intervals of 5 K. The thermal decomposition of the sample was studied using thermogravimetric (TG) analytic technique, the thermal decomposition starts at ca. 418 K and ends at ca. 544 K, the maximum decomposition rate was obtained at 510 K. The order of reaction, preexponential factor and activation energy are n =0.23, A =7. 3 × 107 min -1, E =70.64 KJ/mol, respectively.     

Thermal decomposition and kinetics studies on the 2,2-dinitropropyl acrylate–styrene copolymer and 2,2-dinitropropyl acrylate–vinyl acetate copolymer

In the present work, kinetics of thermal decomposition of 2,2-dinitropropyl acrylate–styrene copolymer (DNPA/St) and 2,2-dinitropropyl acrylate–vinyl acetate copolymer (DNPA/VAc) was investigated by differential scanning calorimetry (DSC). The influence of the heating rate (5, 10, 15, and 20 °C min^?1) on the DSC behavior of the copolymer was verified. The results showed that, as the heating rate was increased, decomposition temperature of the copolymer was increased. Also, the kinetic parameters such as activation energy and frequency factor of the copolymer were obtained from the DSC data by the isoconversional methods proposed by Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO). Average activation energy obtained by KAS and FWO methods for the thermal decomposition reaction of DNPA/St and DNPA/VAc are 157.38 ± 0.27 and 147.67 ± 0.57 kJ mol^?1, respectively. The rate constants for thermal decomposition calculated from the activation parameters showed the structural dependency. The relative stability of two copolymers under 50 °C was in this order: DNPA/St > DNPA/VAc. The results of thermogravimetry (TG) analysis revealed that the main mass changes for DNPA/St and DNPA/VAc occurred in the temperature ranges of 200–270 °C. The DSC-FTIR analysis of DNPA/St indicates that the band intensity of nitro and other groups increased haphazardly from 230 °C due to thermal decomposition.     

Synthesis and some reactions of a 2,2′-biphospholyl

1,1′-Diphenyl-3,3′,4,4′-tetramethyl-2,2′,5,5′-tetrahydro-2,2′-biphosphole obtained by reductive dimerization of the appropriate phosphole has been converted into the corresponding 2,2′-biphosphole by P-bromination followed by dehydrobromination of the resulting P,P′-tetrabromo compound with α-picoline. This 2,2′-biphosphole gives two isomeric P-sulfides upon reaction with sulfur, and a Mo(CO)₄ chelate upon reaction with Mo(CO)₆. Cleavage of the two P-phenyl bonds by lithium in THF yields the corresponding biphospholyl anion, which is converted into a mixture of two isomeric bis(η⁵,η⁵-2,2′-diphosphafulvalene)diirons by treatment with FeCl₂. The reaction of Mn₂(CO)₁₀ in boiling xylene affords a mixture of three complexes, including a (η⁵,η⁵-2,2′-diphosphafulvalene)hexacarbonyldimanganese produced by thermal cleavage of the two PPh bonds. Under CO pressure there is a [1,5] P → C shift of the two phenyl groups, leading to formation of (η⁵,η⁵-3,3′-diphenyl-2,2′-diphosphafulvalene)hexacarbonyldimanganese.     

Synthesis of ruthenium and palladium complexes from glycosylated 2,2′-bipyridine and terpyridine ligands

A series of glucosylated mono- and di-(1H-1,2,3-triazol-4-yl)pyridines were prepared from glucosyl azides and 2-ethynyl and 2,6-diethynyl pyridine via Click reaction. Glucosylation of the silver salt of 4-hydroxy-2,2′-bipyridine with acetobromoglucose afforded the corresponding glucosylated 2,2′-bipyridine. Treatment of five examples of the latter pyridine ligands with [cis-Ru(bipy)2Cl₂], [Ru(tpy)Cl₃] or [Pd(COD)Cl₂] gave the corresponding ruthenium(II) and palladium(II) complexes in 62%-quantitative yield.     

Steric effects on complex formation between nickel(II) and (2-imidazoleazo) benzene, 2,2′-biimidazole and 2,2′-bibenzimidazole

Summary The kinetics and mechanism of reversible complexation of Ni^II with (2-imidazoleazo)benzene (IAB), 2,2-biimidazole (Biim) and 2,2-bibenzimidazole (Bibzm) have been investigated at 15–35 °C, I = 0.30 mol dm^–3. The stability constants, K _M, of the [NiL]²⁺ species vary in the sequence: [Ni(IAB)]²⁺ < [Ni(Bibzm)]²⁺ < [Ni(Biim)]²⁺. The values of the spontaneous dissociation rate constant (k _r) at 25 °C decrease in the sequence: [Ni(IAB)]⁺ > [Ni(Biim)]²⁺ > [Ni(Bibzm)]²⁺. The aquation of [Ni(IAB)]²⁺ is insensitive to acid catalysis, whilst [Ni(Biim)]²⁺ is relatively more susceptible towards acid-catalysed aquation than [Ni(Bibzm)]²⁺. The chelate ring in [NiL]²⁺ (L = IAB, Biim or Bibzm) is sterically strained. The formation of [Ni(IAB)]²⁺ and [Ni(Bibzm)]²⁺ may be chelation controlled while the normal I _d mechanism is supported by our data for [Ni(Biim)]²⁺.     

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Zinc（II） Complex with 2,2′-Diphenic Acid and 2,2′-Bipyridine Ligands

A new dinuclear complex [Zn(dpa)(bipy)(H2O)]2 (dpa = 2,2'-diphenic acid, bipy = 2,2'-bipyridine) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 10.960(2), b = 9.4841(18), c = 20.599(4), β = 104.452(3)o, V = 2073.4(7)3, C48H36N4O10Zn2, Mr = 959.55, Dc = 1.537 g/cm3, μ(MoKα) = 1.225 mm-1, F(000) = 984, Z = 2, the final R = 0.0364 and wR = 0.0843 for 2788 observed reflections (I > 2σ(I)). In the crystal structure, the zinc atom is five-coordinated with two carboxylate oxygen atoms from different dpas, one coordinated water molecule and two nitrogen atoms from bipy ligands, showing a slightly distorted triangular bipyramidal geometry. Furthermore, it exhibits a zero-dimensional network structure with a sixteen-membered ring and shows yellow photoluminescent property at room temperature.     

Synthesis and properties of 2,2′-dipyridyl and 4,4′-dipyridyl complexes with thulium salts

Summary New complexes of 2,2-dipyridyl and 4,4-dipyridyl with thulium salts TmX ₃ (whereX=Cl^–, Br^–, NO ₃ ^– , NCS^–, and ClO ₄ ^– ) have been prepared and their solubilities in water at 21 °C were determined. The IR spectra of these compounds are discussed. The conditions of thermal decomposition of the complexes were also studied.

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Synthese und Eigenschaften von 2,2-Dipyridyl- und 4,4-Dipyridylkomplexen mit Thuliumsalzen

Zusammenfassung Es wurden neue 2,2-Dipyridyl- und 4,4-Dipyridyl-Komplexen mit Thuliumsalzen TmX ₃ (X=Cl^–, Br^– No ₃ ^– , NCS^–, ClO ₄ ^– ) dargestellt und ihre Wasserlöslihkeit bei 21 °C bestimmt. Die IR-Spektren werden diskutiert. Das thermische Verhalten der erhaltenen Komplexe wurde untersucht.

     

Synthesis of 2,2’-Biflavanones from Flavone via Electroreduction and Photolysis

Biflavonoids, widely distributed in natural plants, had strong biological activities including spasmolysis, peripheral vasodilatation, antibradykinin activity and antispasmogenic action against prostaglandin PGE1, inhibition of cyclic GMP and cyclic AMP phosphodiesterase and inhibition of hepatoma cells. Recently, some biflavonoids were demonstrated to enhance suppersion of lymphocyte proliferation, inhibition of phospholipaseCr1, anti-inflammatory activity, anti-HIV activity, anticompleme…     

Cotton-mouton constants and spatial structure of 2,2′- and 4,4′-dipyridyls and their salts in solutions

Magnetic birefringence has been used in studying the spatial structure of a series of dipyridyl derivatives in hydrochloric acid solutions, and also some of their quaternary salts in water. It has been shown that when the change is made from the molecular forms of the 2,2- and 4,4-dipyridyls to their protonated mono and bis derivatives, the angles of rotation of the aromatic rings are very little changed; in the methylated cation, the degree of acoplanarity increases.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2771–2775, December, 1991.     

Mononuclear manganese and tetranuclear copper compounds and their supramolecular networks constructed from hexafluoroglutaric acid and 2,2′-bipyridine

Mn(2,2′-bpy)₂(HFGA) (1) and [Cu₄(μ₃-OH)₂(μ₂-OH)₂(H₂O)₂(2,2′-bpy)₄]?·?2HFGA?·?4H₂O (2) (H₂HFGA?=?hexafluoroglutaric acid and 2,2′-bpy?=?2,2′-bipyridine) have been synthesized and characterized by X-ray structural analyses. 1 is a monomer with six-coordinate Mn²⁺ from two oxygens of HFGA and four nitrogens of two 2,2′-bpy. Complex 2 is tetranuclear with four Cu²⁺ ions bridged by triple-bridging μ₃-OH and double-bridging μ₂-OH. There are two crystallographically independent Cu²⁺ ions in different five-coordinate environments. Cu1 is coordinated by 2,2′-bpy and three OH ligands. Cu2 is coordinated by 2,2′-bpy, two μ₃-OH ligands, and one water molecule. The mononuclear and tetranuclear molecules as building blocks are connected to construct different 3-D supramolecular architectures via noncovalent interactions. Particularly, the lone pair (lp)–π (F···π) interaction in 1 is observed. A hybrid water-anionic tape by linkage of {[(H₂O)₄(HFGA)]₂ ^4?} _n fragments consisting of water dimers and HFGA anions in 2 is observed.     

Synthesis of Polyiodides of N- and S-S-Acetonyl Derivatives of 2,2′-(Disulfanediyl)- and 2,2′-[Alkanediylbis(sulfanyl)]-bisbenzimidazolium

Russian Journal of Organic Chemistry - 2,2′-(Disulfanediyl)- and 2,2′-[alkanediylbis(sulfanyl)]-bisbenzimidazoles react with aliphatic, aromatic, and heterocyclic α-iodoketones in...