- Novel 1,3-diethyl-2-thiobarbiturates of 2,2′-bipyridine and 1,10-phenanthroline: Synthesis, crystal structure and thermal stability
-
Co-crystallization of 1,3-diethyl-2-thiobarbituric acid (HDetba) with 2,2′-bipyridine (Bipy) and 1,10-phenanthroline (Phen) results in preparing a salt co-crystal, BipyH(Detba)(HDetba) (1), and the salt, PhenH(Detba)·H2O (2). The compounds are characterized by single–crystal and powder X–ray diffraction and TG-DSC. The nitrogen atoms of BipyH+ adopt a cis conformation and the N–C–C–N torsion angle is ?17.3(1)o. There are six intermolecular hydrogen bonds O–H?O, N–H?O, C–H?O and C–H?S in (1) which form a 2D plane network. One Detba– ion and one HDetba molecule form a pair by means of O–H?O hydrogen bonds. Detba? anions in (2) do not form dimers, they are connected by N–H?O, C–H?S, and C–H?O hydrogen bonds only with PhenH+ cations and water molecules which form a 3D net. Different π?π interactions between the rings are found in (1)?(2).
- Golovnev, Nicolay N.,Molokeev, Maxim S.,Sterkhova, Irina V.,Lesnikov, Maxim K.
-
-
Read Online
- Deep eutectic solvents used as catalysts for synthesis of 1,10-phenanthroline by improved Skraup reaction
-
Abstract: In this study, three different choline chloride-based deep eutectic solvents were synthesized. And it is the first time to synthesize 1,10-phenanthroline through an improved Skraup reaction using deep eutectic solvent as the new catalyst from acrolein and 8-aminoquinoline. The deep eutectic solvents were characterized by Fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (1H NMR), pH/mV meter, and thermogravimetric analysis (TGA). The research results show that the deep eutectic solvent formed by sulfanilic acid and choline chloride has the strongest acidity and highest catalytic active among the three deep eutectic solvents. Besides, the impacts of reaction parameters and molar ratio of raw materials on the reaction were also investigated. Under the optimized reaction conditions, the maximum selectivity and yield of 1,10-phenanthroline were achieved as 84.6 and 75.6%, respectively. The synthesis method, meanwhile, also has simple preparation process and low cheaper catalyst raw. Graphical abstract: [InlineMediaObject not available: see fulltext.] Replacing traditional sulfuric acid and hydrochloric acid with deep eutectic solvents (DESs) as new catalysts provides a more efficient, greener and more economical strategy for the synthesis of 1,10-phenanthroline by a new improved Skraup reaction.
- Wu, Mingliang,Bai, Yuansheng,Chen, Xuejun,Wang, Qingyin,Wang, Gongying
-
-
Read Online
- Palladium-(II) and -(IV) complexes as intermediates in catalytic C-C bond-forming reactions
-
Palladium-(II) and -(IV) species active as catalysts in C-C bond-forming reactions have been stabilized by adding phenanthroline as a ligand.The complexes formed have been characterized by chemical and spectroscopic methods and their formation and subsequent fate have been monitored by 1H NMR spectroscopy.
- Catellani, Marta,Chiusoli, Gian Paolo
-
-
Read Online
- Electrochemical Study of Reaction of Hyperoxide with Tris(1,10-phenanthroline)iron(II) in Dimethyl Sulfoxide
-
Reaction of hyperoxide with Fe(phen)32+ in DMSO was studied by polarography, cyclic voltammetry, and spectroscopy.Voltammetric study of oxygen showed that disproportionation of hyperoxide is promoted by Fe(phen)32+.Controlled potenti
- Umemoto, Kisaburo,Saeki, Toyohumi,Matsuura, Niro,Motegi, Katsue
-
-
Read Online
- INCLUSION COMPOUNDS OF ORGANIC AZOCHROMOPHORES IN THE CAVITIES OF METAL-ORGANIC FRAMEWORKS (Cr,?Al)– MIL-101: SYNTHESIS AND PHOTOCHEMICAL STUDIES
-
Abstract: Inclusion compounds of nitrogen-containing aromatic chromophores 4,4′-bispyridylethylene (bpe) and 4,4′-azopyridine (apy) in the cavities of mesoporous metal-organic frameworks Cr–MIL-101 and Al–MIL-101 are prepared and characterized by elemental analysis and nitrogen adsorption methods with a goal of finding approaches to the design of solid photochromic materials combining the benefits of photochromes in liquid solutions (high quantum yields) and in solid states (increased resistance to photodegradation). Photochemical properties of these compounds are qualitatively studied. Compound apy@Al–MIL-101 exhibits higher photoactivity than polycrystalline apy. Three other inclusion compounds are not photoactive. Possible reasons of the lack of photoactivity in these compounds are discussed. [Figure not available: see fulltext.]
- Glebov, E. M.,Kovalenko, K. A.,Orlioglo, B. M.
-
p. 152 - 163
(2022/03/09)
-
- Cationic tetra-and pentacoordinate complexes of nickel based on POCN-and POCOP-Type pincer ligands: Synthesis, characterization, and ligand exchange studies
-
Stirring acetonitrile solutions of the charge-neutral pincer complexes (POCN)NiBr (1, POCN = κP,κC,κN-{2-(i-Pr)2PO,6-CH2{c-N(CH2)5}-C6H3) and (POCOP)NiBr (2, POCOP = κP,κC,κP′-2,6-(i-Pr2OP)2C6H3) with AgSbF6 facilitates Br- abstraction to give the corresponding cationic acetonitrile adducts [(POCN)Ni(NCMe)]+, 1a, and [(POCOP)Ni(NCMe)]+, 2a. Treating 1a and 2a with pyridine (py), 2,2′-bipyridine (bipy), phenanthroline (phen), or 4,4′-bipyridine (bipy?) gave the corresponding monocationic adducts [(POCN or POCOP)Ni(ligand)]+ (ligand = py: 1b and 2b; κN,κN′-bipy: 1c and 2c; κN,κN′-phen: 1d and 2d) and the dicationic dinuclear adducts [(POCN or POCOP)2Ni2(μ-bipy?)]2+ (1e and 2e). The new adducts 1a-1d and 2b-2e have been characterized by NMR spectroscopy; complex 1e proved to be insoluble and could not be analyzed by NMR. Single crystal X-ray diffraction studies were used to establish the solid-state structures of 1a-1e, and 2b-2d. UV-vis spectra have also been recorded for the pentacoordinated complexes 1c, 1d, 2c, and 2d. Studying the equilibria that govern the displacement of halides in (pincer)NiX (X = Cl, Br) by the in-coming nucleophiles py, bipy, and phen has allowed us to determine the following order for the relative nucleophilicities of the ligands involved in the halide substitution equilibria: Cl- > Br- > phen > bipy ? py > MeCN. Similar Keq measurements showed that cationic species are better stabilized with the POCN platform compared to POCOP. This implies that POCN is a better net donor of electron density compared to POCOP, such that the relative Lewis acidity (electrophilicity) of the cationic fragments should follow the order [(POCOP)Ni]+ > [(POCN)Ni]+. Cyclic voltammetry measurements on the bipy adducts showed reversible, one-electron oxidation events occurring at a lower value for [(POCN)Ni(bipy)]+, implying a more electron-rich Ni(ii) centre with POCN vs. POCOP. Consistent with these assertions, mixing (POCN)NiBr and [(POCOP)Ni(phen)]+ in acetonitrile gave [(POCN)Ni(phen)]+ and (POCOP)NiBr. Similarly, the Keq value of 0.19 for the equilibrium exchange (POCN)NiCl + (POCOP)NiBr ? (POCN)NiBr + (POCOP)NiCl indicates that the [(POCOP)Ni]+ fragment is better stabilized by Cl-vs. Br-. These exchange reactions do not occur in THF or CH2Cl2, implying that they are driven by the nucleophilic character of the solvent. This journal is
- Rahimi, Naser,Zargarian, Davit
-
supporting information
p. 15063 - 15073
(2021/09/04)
-
- Iron(II)-Catalyzed Aerobic Biomimetic Oxidation of N-Heterocycles
-
Herein, an iron(II)-catalyzed biomimetic oxidation of N-heterocycles under aerobic conditions is described. The dehydrogenation process, involving several electron-transfer steps, is inspired by oxidations occurring in the respiratory chain. An environmentally friendly and inexpensive iron catalyst together with a hydroquinone/cobalt Schiff base hybrid catalyst as electron-transfer mediator were used for the substrate-selective dehydrogenation reaction of various N-heterocycles. The method shows a broad substrate scope and delivers important heterocycles in good-to-excellent yields.
- Manna, Srimanta,Kong, Wei-Jun,B?ckvall, Jan-E.
-
supporting information
p. 13725 - 13729
(2021/09/08)
-
- An effective non-chromatographic method for the purification of phenanthrolines and related ligands
-
1,10-Phenanthrolines are widely employed as ligands, but their use on a large scale is constrained by their difficult purification, which usually requires lengthy chromatographic separations. Herein, we describe a purification strategy that takes advantage of the high stability and low solubility of phenanthroline complexes to separate them from the by products of their synthesis. The formation of ZnCl2 complexes was employed, from which the free ligand can be recovered by reaction with aqueous NH3 in a biphasic CH2Cl2/H2O system. The same strategy was also successfully employed to purify related quinolino-guanidine ligands, demonstrating that the procedure is of general applicability.
- Ferretti, Francesco,Ragaini, Fabio
-
-
- METHOD OF PRODUCING PHENANTHRILINE AND DERIVATIVE THEREOF
-
An application of the present invention provides a method of producing ortho-aminoarenecarbaldehyde, ortho-aminoarenecarbaldehyde produced therefrom, and a method for producing phenanthroline and derivatives thereof which can be utilized in the field of OLED and diagnostic reagents using the same. The application comprises: a first step of producing a compound of formula 2 by oxidizing a compound of formula 1 with NaIO_4; and a second step of producing a compound of formula 3 by reducing the compound of formula 2 with nascent hydrogen generated by acid and metal.COPYRIGHT KIPO 2020
- -
-
Paragraph 0107-0112
(2020/05/20)
-
- Synthesis and Photochemical Properties of Manganese(I) Tricarbonyl Diimine Complexes Bound to Tetrazolato Ligands
-
Ten manganese(I) tricarbonyl diimine complexes bound to variably functionalised 5-aryl-tetrazolato ligands were prepared, and their photochemical properties were investigated. Upon exposure to light at 365 nm, each complex decomposed to its free diimine and tetrazolato ligands, simultaneously dissociating three CO ligands, as evidenced by changes in the IR spectra of the irradiated complexes over time. The anti-bacterial properties of one of these complexes were tested against Escherichia coli. While the complex displayed no effect on the bacterial growth in the dark, pre-irradiated solutions inhibited bacterial growth. Comparative studies revealed that the antibacterial properties originate from the presence of free 1,10-phenanthroline.
- Stout, Matthew J.,Stefan, Alessandra,Skelton, Brian W.,Sobolev, Alexandre N.,Massi, Massimiliano,Hochkoeppler, Alejandro,Stagni, Stefano,Simpson, Peter V.
-
supporting information
p. 292 - 298
(2020/01/25)
-
- Catalytic Aerobic Dehydrogenatin of N-Heterocycles by N-Hydoxyphthalimide
-
Catalytic methods for the aerobic dehydrogenation of N-heterocycles are reported. In most cases, indoles are accessed efficiently from indolines using catalytic N-hydroxyphthalimide (NHPI) as the sole additive under air. Further studies revealed an improved catalytic system of NHPI and copper for the preparation of other heteroaromatics, for example quinolines. (Figure presented.).
- Chen, Weidong,Tang, Hao,Wang, Weilin,Fu, Qiang,Luo, Junfei
-
supporting information
p. 3905 - 3911
(2020/08/10)
-
- Potassium tert-Butoxide-Promoted Acceptorless Dehydrogenation of N-Heterocycles
-
Potassium tert-butoxide-promoted acceptorless dehydrogenation of N-heterocycles was efficiently realized for the generation of N-heteroarenes and hydrogen gas under transition-metal-free conditions. In the presence of KOtBu base, a variety of six- and five-membered N-heterocyclic compounds efficiently underwent acceptorless dehydrogenation to afford the corresponding N-heteroarenes and H2 gas in o-xylene at 140 °C. The present protocol provides a convenient route to aromatic nitrogen-containing compounds and H2 gas. (Figure presented.).
- Liu, Tingting,Wu, Kaikai,Wang, Liandi,Yu, Zhengkun
-
p. 3958 - 3964
(2019/08/01)
-
- Preparation of a New Friedl?nder Synthon, 2,3-Diaminobenzene-1,4-dicarbaldehyde, and Its Application towards Synthesis of 1,10-Phenanthrolines and Related Cyclophane
-
A new Friedl?nder synthon, 2,3-diaminobenzene-1,4-dicarbaldehyde, was prepared from p-xylene in 4 steps, of which the Friedl?nder reaction with acetaldehyde and acetone in a Schulenk bottle afforded 1,10-phenathroline and neocuprine in 44% and 82% yield, respectively. The scope of the Friedl?nder reactions of 2,3-diaminobenzene-1,4-dicarbaldehyde, including the synthesis of hexaazacyclic cyclophane with 1,10-phenanthroline and pyridine units, was described.
- Lu, Yang,Jahng, Yurngdong
-
p. 221 - 225
(2019/02/03)
-
- Diflunisal-adjoined cobalt(iii)-polypyridyl complexes as anti-cancer stem cell agents
-
We report a novel series of cobalt(iii)-polypridyl complexes, 4-6, that can selectively release diflunisal, a nonsteroidal anti-inflammatory drug, under reducing conditions. Remarkably, the 1,10-phenanthroline-bearing complex 5 displays selective potency towards hard-to-kill cancer stem cells (CSCs) (IC50 = 2.1 ± 0.1 μM) over bulk cancer (IC50 = 3.9 ± 0.2 μM) and normal cells (IC50 = 21.2 ± 1.3 μM). This complex induces CSC apoptosis by DNA damage and cyclooxygenase-2 inhibition.
- Abe, David O.,Eskandari, Arvin,Suntharalingam, Kogularamanan
-
supporting information
p. 13761 - 13765
(2018/10/20)
-
- A green organic boron reagent carbon boron key cracking hydrogenation of the new method (by machine translation)
-
The invention relates to a kind of green, efficient organic boron reagent carbon boron key cracking hydrogenation of the new method. The method uses a cheap and easily obtained inorganic base as catalyst, common organic alcohol as the reaction solvent and a hydrogen source, is placed under the environment of air can be conveniently catalytic organic boric acid or borate generating carbon boron key cracking hydrogenation reaction, the reaction substrate universality is wide, functional group compatibility outstanding. System realizing metallic catalytic various boric acid and boric acid ester in the fracture of the carbon boron key reaction, also overcome the traditional method requires the use of greatly excessive inorganic alkali, organic acid in great harm to the environment or complex metal catalyst to the limitations of the b-hydrogenation, laboratory preparation and industrial production organoboron reagent of the b-hydrogenation reaction provides a completely new strategy. (by machine translation)
- -
-
Paragraph 0062; 0063
(2017/10/09)
-
- Controlled Energy Transfer from a Ligand to an EuIII Ion: A Unique Strategy to Obtain Bright-White-Light Emission and Its Versatile Applications
-
A new diphenylamine-functionalized ancillary-ligand-coordinated europium(III) β-diketonate complex showed incomplete photoexcitation energy transfer from a ligand to a EuIII ion. A solvatochromism study led to a balancing of the primary colors to obtain single-molecule white-light emission. Thermal-sensing analysis of the europium complex was executed. The europium complex, conjugated with a near-UV-light-emitting diode (395 nm), showed appropriate white-light-emission CIE color coordinates (x = 0.34 and y = 0.33) with a 5152 K correlated color temperature.
- Boddula, Rajamouli,Singh, Kasturi,Giri, Santanab,Vaidyanathan, Sivakumar
-
supporting information
p. 10127 - 10130
(2017/09/12)
-
- Palladium Nanoparticles Stabilized by Metal–Carbon Covalent Bonds as an Expeditious Catalyst for the Oxidative Dehydrogenation of Nitrogen Heterocycles
-
The first method for the dehydrogenation of nitrogen heterocycles catalyzed by a palladium nanocatalyst was developed. Carbon–metal covalent-bond-stabilized nanoparticles were found to be efficient for the dehydrogenation process in the presence of tert-butyl hydroperoxide. A variety of N-heterocycles were transformed into functionalized quinolines in medium to excellent yields in water as the solvent under mild conditions by a simple operation.
- Sun, Xiao-Tao,Zhu, Jie,Xia, Yun-Tao,Wu, Lei
-
p. 2463 - 2466
(2017/07/12)
-
- Bimetallic C-C Bond-Forming Reductive Elimination from Nickel
-
Ni-catalyzed cross-coupling reactions have found important applications in organic synthesis. The fundamental characterization of the key steps in cross-coupling reactions, including C-C bond-forming reductive elimination, represents a significant challenge. Bimolecular pathways were invoked in early proposals, but the experimental evidence was limited. We present the preparation of well-defined (pyridine-pyrrolyl)Ni monomethyl and monophenyl complexes that allow the direct observation of bimolecular reductive elimination to generate ethane and biphenyl, respectively. The sp3-sp3 and sp2-sp2 couplings proceed via two distinct pathways. Oxidants promote the fast formation of Ni(III) from (pyridine-pyrrolyl)Ni-methyl, which dimerizes to afford a bimetallic Ni(III) intermediate. Our data are most consistent with the subsequent methyl coupling from the bimetallic Ni(III) to generate ethane as the rate-determining step. In contrast, the formation of biphenyl is facilitated by the coordination of a bidentate donor ligand.
- Xu, Hongwei,Diccianni, Justin B.,Katigbak, Joseph,Hu, Chunhua,Zhang, Yingkai,Diao, Tianning
-
supporting information
p. 4779 - 4786
(2016/05/09)
-
- Quinoline and phenanthroline preparation starting from glycerol via improved microwave-assisted modified Skraup reaction
-
An efficient "green" modified Skraup reaction in neat water was developed using inexpensive, abundant and environmentally-friendly glycerol under microwave irradiation conditions. Starting from aniline derivatives, various quinolines were obtained in 10-66% yields. The use of nitroaniline led to the corresponding phenanthrolines in 15-52% yields, respectively. This journal is the Partner Organisations 2014.
- Saggadi, Hanen,Luart, Denis,Thiebault, Nicolas,Polaert, Isabelle,Estel, Lionel,Len
-
p. 21456 - 21464
(2014/06/10)
-
- PARTIALLY ABSORBABLE FIBER-REINFORCED COMPOSITES FOR CONTROLLED DRUG DELIVERY
-
This invention describes a partially absorbable, fiber-reinforced composite in the form of a ring, or a suture-like thread, with modified terminals for use as a controlled delivery system of at least one bioactive agent, wherein said composite comprising an absorbable fiber construct capable of providing time-dependent mechanical properties of a biostable elastomeric matrix containing an absorbable microparticulate ion-exchanger to modulate the release of the bioactive agent(s) for a desired period(s) of time at a specific biological site; this can be a vaginal canal, peritoneal cavity, scrotum, prostate gland, an ear loop or subcutaneous tissue. Such drug delivery systems can be used for the local administration of at least one bioactive agent, including those used as contraceptive, antimicrobial, anti-inflammatory and/or antiviral agents as well as for cancer treatment.
- -
-
Page/Page column
(2013/07/25)
-
- Copper(I) enolate complexes in α-arylation reactions: Synthesis, reactivity, and mechanism
-
Copper is all bound up: The copper-catalyzed α-arylation of carbonyl compounds occurs through oxidative addition of iodoarenes to the C-bound Cu I enolate species 1 to form an aryl-CuIII intermediate (see scheme). Computational results provide insight into the origins of the relative reactivity of various CuI enolate complexes in the reactions with iodoarenes. Copyright
- Huang, Zheng,Hartwig, John F.
-
supporting information; experimental part
p. 1028 - 1032
(2012/03/09)
-
- Convenient synthesis of 5-aryl(alkyl)sulfanyl-1,10-phenanthrolines from 5,6-epoxy-5,6-dihydro-1,10-phenanthroline, and their activity towards fungal β-d-glycosidases
-
A broad series of novel 5-aryl(alkyl)sulfanyl-1,10-phenanthrolines has been prepared by a new simple procedure: a treatment of the commercially available 5,6-epoxy-5,6-dihydro-1,10-phenanthroline with various thiols in the presence of a base. Other functional groups attached to the thiol allow a use of the products as building blocks in synthesis of versatile ligands and in functionalization of surfaces. The synthesized phenanthrolines showed a moderate ability as activators or inhibitors of fungal β-d-glucosidases and β-d-galactosidases.
- Dotsenko, Irina A.,Curtis, Matthew,Samoshina, Nataliya M.,Samoshin, Vyacheslav V.
-
scheme or table
p. 7470 - 7478
(2011/10/17)
-
- Reactions of hydridochlorosilanes with 2,2′ -bipyridine and 1.10-phenanthroline: Complexation versus dismutation and metal-catalyst-free 1.4-hydrosilylation
-
Stable in the solid state and isolable in high yields are adducts of H 2SiCI2, HSiCl3, and RSiCl3 (R = Me, Ph) with the N, N'-chelating ligands 1,10-phenanthroline (phen; 1c), 2,2'-bipyridine (bipy; 1b), and (to a limited extent) N,N,N, Ntetramethylethylenediamine (tmeda; 1a). The products were comprehensively characterized via multinuclear solution and solid-state NMR spectroscopy, including analysis of the 29Si NMR chemical shift anisotropy tensors, Raman spectroscopy, elemental analyses, and, for SiCI4(phen) (2c), HSiCl3(bipy) (3b), H2SiCl2(bipy) (4b), MeSiCl3(phen) (5c), and PhSiCl3(phen) (6c), single-crystal X-ray structure analyses. The latter revealed that the nonchlorine substituents (i.e., H, Me, and Ph) are exclusively trans-disposed to the N-donor atoms of the chelating ligands. A dismutation of the complexes HXSiCl2(bipy) and HXSiCl2(tmeda) (X = H or Cl) was observed in polar solvents at elevated temperatures. This reaction is more pronounced when phen is used instead of bipy or tmeda. For MeHSiCl2(phen), in addition to undergoing H-Cl redistribution accompanied by the formation of 5c, an unexpected 1,4-hydrosilylation was observed. The latter was proven NMR-spectroscopically and by a single-crystal X-ray structure analysis of the product MeSiCl 2(4H-phen) (7), a pentacoordinated silicon compound with a trigonal-bipyramidal arrangement of the subsituents and the methyl group located in an equatorial position.
- Fester, Gerrit W.,Eckstein, Jana,Gerlach, Daniela,Wagler, Joerg,Brendler, Erica,Kroke, Edwin
-
scheme or table
p. 2667 - 2673
(2010/06/20)
-
- Chelation-assisted electrocyclic reactions of 3-alkenyl-2,2′- bipyridines: An efficient method for the synthesis of 5,6-dihydro-1,10- phenanthroline and 1,10-phenanthroline derivatives
-
An efficient method for the synthesis of substituted 5,6-dihydro-1,10- phenanthrolines and 1,10-phenanthrolines has been developed by means of the chelation-assisted photochemical electrocyclic reactions of 3-alkenyl-2, 2′-bipyridines. The Royal Society o
- Takahashi, Akihiko,Hirose, Yuko,Kusama, Hiroyuki,Iwasawa, Nobuharu
-
p. 609 - 611
(2008/09/20)
-
- A new approach to the 1,10-phenanthroline core
-
A protocol for the synthesis of substituted 1,10-phenanthrolines is reported. The phenanthroline scaffold has been obtained constructing the central cycle starting from two pyridine rings. The method is hinged upon the intramolecular coupling of cis-1,2-di(2-bromo-3-pyridyl)ethenes that are in turn obtained from the Wittig reaction of 2-bromonicotinaldehydes with phosphonium salts prepared from 2-bromo-3-(bromomethyl)pyridines. Yields up to 75% have been obtained.
- Chelucci, Giorgio,Addis, Daniele,Baldino, Salvatore
-
p. 3359 - 3362
(2008/02/12)
-
- Friedlaender reactions of triacetylmethane- unusual distribution of products-
-
Friedlaender reactions of triacetylmethane with selected β-amino-α,β-unsaturated aldehydes afforded pyridoheterocycles and their 2-methyl derivatives instead of triheteroarylmethane.
- Rahman, A.F.M. Motiur,Kwon, Youngjoo,Jahng, Yurngdong
-
p. 2777 - 2782
(2007/10/03)
-
- Thermodynamic studies of the binding of bidentate nitrogen donors with methyltrioxorhenium (MTO) in CHCl3 solution
-
Methyltrioxorhenium (MTO) adduct formation with bidentate nitrogen donors 2,2′-bipyridine (bpy), 4,4′-dimethyl-2,2′-bipyridine (Me 2bpy), 4,4′-di-tert-butyl-2,2′-bipyridine ( tBu2bpy), 1,10-phenanthroline (phen), 5-methyl-
- Nabavizadeh, S. Masoud
-
p. 1644 - 1648
(2007/10/03)
-
- Oxidation catalyst and oxidation process using the same
-
In the presence of (1) an oxidation catalyst comprising a crystalline complex of manganese with an N,N′-disalicylidenediamine (e.g., N,N′-disalicylidene C2-8alkylenediamines and N,N′-disalicylidene C6-12arylenediamines), or (2) an oxidation catalyst comprising the above complex and a basic nitrogen-containing compound, a substrate (e.g., β-isophorone or a derivative thereof) is oxidized with molecular oxygen to produce a corresponding oxide (e.g., ketoisophorone). Ketoisophorone can be obtained from β-isophorone with high conversion and high selectivity.
- -
-
-
- Oxidation catalytic system and process for producing ketoisophorone using the same
-
In the presence of a catalytic system comprising a cyclic base and a complex of a transition metal with an N,N'-disalicylidenediamine, ketoisophorone or a derivative thereof is produced by oxidizing beta -isophorone or a derivative thereof with molecular oxygen with controlling the water content of a reaction system to 1% by weight or less at the initial stage of the reaction. Moreover, the above catalytic system further comprises a basic nitrogen-containing compound. The complex may be an N,N'-disalicylidene C2-5 alkylenediamine complex with manganese, iron, cobalt, copper, or vanadium. The cyclic base may be an alicyclic or aromtaic compound having at least two nitrogen atoms. As the basic nitrogen-containing compound, a Schiff base such as an imino compound and an anil compound can be used. The proportion of the nitrogen-containing compound to the complex is about 0.1/1 to 20/1 (molar ratio). With the above oxydation catalytic system, there can be obtained ketoisophorone and derivatives thereof with high efficiency.
- -
-
-
- Formation of radical anions on the reduction of carbonyl-containing perfluoroaromatic compounds in aqueous solution: A pulse radiolysis study
-
Radical anions are formed on addition of hydrated electrons to pentafluoroacetophenone (PFA) and pentafluorobenzaldehyde (PFB) in aqueous solutions. On the other hand, addition of hydrated electrons to pentafluorobenzoic acid (PFBA) leads to rapid fluoride elimination. The spectrum of the radical anion of PFA has λmax at 300 and 440 nm with absorption coefficient at 440 nm ε440 = 2100 L mol-1 cm-1. PFA?- decays with a rate constant of (7 ± 3.0) × 103 s-1. It has a pKa = 7.5 and the spectrum of the conjugate acid has λmax at 270 and 460 nm with ε460 = 900 L mol-1 cm-1. The spectrum of the radical anion of PFB has λmax at 285 and 430 nm with ε430 = 800 L mol-1 cm-1. PFB?- decays with a rate of (4 ± 2) × 103 s-1. It has a pKa = 7.2 and the spectrum of the conjugate acid has weak absorption at 330 nm. Evidence for the formation of the radical anion was obtained from intermolecular electron transfer from the radical anions of PFA and PFB top-benzoquinone (Q), methyl viologen (MV2+), and 9,10-anthraquinone-2-sulfonate (AQS-). Strong reductants derived from reduction of 2,2-bipyridine (BpyH?) and 1,10-phenanthroline (PhenH?) can reduce both PFA and PFB. From the kinetics of these electron transfer reactions the reduction potentials of PFA and PFB have been determined to be -0.86 ± 0.1 and -0.75 ± 0.1 V vs NHE at pH 9.4. Addition of OH? radical to the aromatic ring of these fluorinated compounds led to rapid HF elimination and the formation of phenoxyl radicals, and addition of H? atoms led to the formation of cyclohexadienyl radical.
- Shoute, Lian C. T.,Mittal, Jai P.
-
p. 14022 - 14027
(2007/10/03)
-
- Thermal Decomposition of Phenanthroline Complexes of Cobalt(II) and Nickel(II) Chlorides in Inert Atmosphere
-
Thermal decomposition of the phenanthroline (phen) complexes Co(phen)3Cl2 and Ni(phen)3Cl2 in argon in the temperature range 20 - 900°C is studied. On the basis of the data of differential thermal, elemental, and X-ray powder diffraction analyses, and IR and diffuse reflection spectroscopies, the composition and structure of the products of each decomposition stage are found. In both cases, the final product of pyrolysis is a finely dispersed metal incorporated in the matrix of the nitrogen-containing graphitelike pyropolymer.
- Kryatova, O. P.,Mashkin, O. A.,Kalibabchuk, V. A.
-
p. 1895 - 1898
(2008/10/08)
-
- Photodynamic herbicides
-
Herbicidal compositions comprising one or more compounds selected from the group consisting of δ-aminolevulinic acid, inducers of δ-aminolevulinic acid, enhancers of δ-aminolevulinic acid conversion to photodynamic tetrapyrroles, and inhibitors of conversion of divinyl tetrapyrroles to monovinyl tetrapyrroles; and methods of making and using same.
- -
-
-
- Cyclic compounds for forming complexes with urea, guanidine and amidine derivatives
-
A molecule capable of forming stable complexes with urea, guanidine or amidine compounds and the acid addition salts thereof comprises a nucleus of heterocyclic rings.
- -
-
-
- Photochemistry of hetero-tris-chelated ruthenium(II) polypyridine complexes in dichloromethane
-
The results of an investigation of the photochemical and photophysical properties of a series of complexes of the type [RuL2L′]Cl2 are reported, where L and L′ are bipyridine, phenanthroline, and methyl and phenyl derivatives of those ligands. All measurements were conducted in CH2Cl2. Luminescence lifetime and quantum yield data indicate that the ligand which accepts the electron in the localized MLCT excited state plays a significant role in the excited-state decay. HPLC analysis of the organic photoproducts from mixed-ligand complexes shows that flexible bipyridyl ligands are preferentially photolabilized, consistent with a dissociative mechanism involving an open-ended bipyridine in the transition state.
- Jones Jr., Wayne E.,Smith, Robert A.,Abramo, Marsha T.,Williams, Michael D.,Van Houten
-
p. 2281 - 2285
(2008/10/08)
-
- Photoaquation reactions of chromium(III) polypyridine complexes induced by sequential biphotonic irradiations
-
The long-lived, low-lying doublet states of Cr(III) polypyridine complexes have been generated and irradiated by using sequential biphotonic techniques. The detection of products and the time-resolved spectroscopy of the processes have shown that biphotonic irradiation induces a ligand photolabilization independent of acid concentration. Such a reaction cannot be associated with the photolabilization induced in monophotonic irradiations with low light intensities and has been related to processes initiated in upper excited states.
- Van Vlierberge,Ferraudi
-
p. 1386 - 1389
(2008/10/08)
-
- Hydrophobic and steric effects on the ion-pair formation of tris(1,10-phenanthroline)iron(II) and arenesulfonate ions. Kinetic determination of the formation constants of the ion pairs and a 1H NMR study of their structures
-
Ion-pair formation constants (K) for Fe(phen)32+ and six kinds of arenesulfonate ions were obtained from kinetic studies of the aquation of the complex ion in aqueous sodium arenesulfonate solutions: K = 5 ± 1, 13 ± 2, 28 ± 5, 19 ± 3, 8 ± 2, and 5 ± 1 mol-1 dm3 for benzene-, 4-methylbenzene-, 4-ethylbenzene-, 2,4-dimethylbenzene-, 1-naphthalene-, and 2-naphthalenesulfonate, respectively. An arenesulfonate of greater hydrophobicity showed a larger formation constant, except that small formation constants were shown by bulky naphthalenesulfonates. The formation constant was smaller for an arenesulfonate than for an alkanesulfonate with the same number of carbon atoms. The 1H NMR signal of arenesulfonate in the ion pair was found to shift upfield. Comparison of the observed shifts with those calculated on the basis of the current loop model supported a model of the ion pair in which the arenesulfonate ion lies in the hydrophobic cavity between two phenanthroline ligands of the complex ion with the sulfonate group directed outside the cavity.
- Tachiyashiki, Satoshi,Yamatera, Hideo
-
p. 3209 - 3211
(2008/10/08)
-
- Kinetics of Dissociation of Tris-(1,10-Phenanthroline)-Iron(III) Sulphate in Aqueous Acetic Acid Medium
-
The kinetics of dissociation of tris-(1,10-phenanthroline)-iron(III) in aqueous acetic acid medium has been studied as a function of H+.The reaction is first order in ferriin and first order in acetic acid and further the reaction rate is inversely dependent on H+.A probable mechanism has been proposed making use of the steady-state hypothesis.
- Sriramam, K.,Sarma, B.S.R.,Kalidas, K.
-
-
- OXIDATION-REDUCTION MECHANISMS - INNER-SPHERE AND OUTER-SPHERE ELECTRON TRANSFER IN THE REDUCTION OF IRON(III), RUTHENIUM(III), AND OSMIUM(III) COMPLEXES BY ALKYL RADICALS. MECHANISMS -
-
Alkyl radicals are readily oxidized by the tris(phenanthroline) and tris(bipyridine) complexes ML//3**3** plus of iron(III), ruthenium(III), and osmium(III) in acetonitrile solution, the second-order rate constants easily exceeding 10**6 M** minus **1s** minus **1 at 25 degree C. Two oxidative processes are identified as (a) ligand substitution on the coordinated 1,10-phenanthroline to yield various alkylphenanthrolines and (b) cation formation to afford alkenes and N-alkylacetamides (after hydrolysis). Cation formation is characterized by extensive skeletal rearrangement of neopentyl, isobutyl, and n-propyl groups, whereas ligand substitution by the same alkyl radicals occurs without any rearrangement.
- Rollick,Kochi
-
p. 1319 - 1330
(2007/10/02)
-
- Effect of Nucleophiles on the Rates of Dissociation and Racemization of the Tris(1,10-phenanthroline)iron(II) Ion in Aqueous Solutions
-
The rates of dissociation and racemization of the tris(1,10-phenanthroline)iron(II) ion were obtained in aqueous solutions containing fourteen ikinds of nucleophile.They ranged from 0.7 to 9.3 and from 0.9 to 3.2 times the rates in pure water, respectively.The results were analyzed by considering simultaneous reactions of free and ion-paired complex ions.The rate constants of the dissociation (ligand release) of the complex existing in ion-pairs increased in the following order of the counter-ions: I--------- ca.CN-; here H2O is regarded as a nucleophile for the free complex ion.This order is similar to that of proton affinities of nucleophiles.The results show that the dissociation is accelerated by ? donation from the nucleophile, suggesting an ion-pair interchange mechanism.The inramolecular racemization rate constant, given by total recemization rate constant minus dissociation rate constant, increased in the following order of nucleophiles: OH- ca.CN- ca.F- ca.Cl- - ca.NO2- - - - - - ca.SeCN- a greater effect than their basicity.The operation of ? interaction between the complex ion and the nucleophile in the transition state is also suggested.The ion-association constants obtained from the rate data were in the range of 1 to 8 (I=1.0, 32.0 deg C).
- Tachiyashiki, Satoshi,Yamatera, Hideo
-
p. 1014 - 1021
(2007/10/02)
-
- A Search for Lone-Pair Interactions in Forward and Reverse Menschutkin Reactions of Some Diaza Heterocycles
-
The rates of methylation (forward reaction) of phthalazine (1), 1,8-naphthyridine (2), 1,10-phenanthroline (3), and of some ring methyl derivatives are compared with the rates of demethylation of the corresponding N-methyl quaternary iodides.It was observed for (2), and especially for (3), that a nitrogen lone pair in place of a CH group (quinoline and 8-methylquinoline, respectively) aids the forward reaction but does not have a commensurate retarding effect on the reverse process.In contrast to (3), 2,2'-bipyridine showed behaviour typical of α-substituted pyridines.The introduction of a 2-methyl group into (3) had an appreciable rate-enhancing effect on methylation (at N 10) and this is interpreted as evidence for lone-pair cooperativity in the forward reaction
- Deady, Leslie W.
-
p. 163 - 170
(2007/10/02)
-
- The kinetics of replacement reactions of complexes of the transition metals with 1,10-phenanthroline and 2,2′-bipyridine
-
The kinetics of formation and dissociation of metal complexes of 1,10-phenanthroline, 2,2′-bipyridine, and some related ligands have been measured by the stopped-flow method. The second-order formation rate constant for the mono complex increases in the s
- Holyer,Hubbard,Kettle,Wilkins
-
p. 929 - 935
(2008/10/08)
-
