bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvent‐Induced Helical Assembly and Reversible Chiroptical Switching of Chiral Cyclic‐Dipeptide‐Functionalized Naphthalenediimides
Authors: Manchineella Shivaprasad , Prathyusha V. , Priyakumar U. Deva , Govindaraju T. 
Published: November 2013

AbstractUnderstanding the roles of various parameters in orchestrating the preferential chiral molecular organization in supramolecular self‐assembly processes is of great significance in designing novel molecular functional systems. Cyclic dipeptide (CDP) chiral auxiliary‐functionalized naphthalenediimides (NCDPs 1–6) have been prepared and their chiral self‐assembly properties have been investigated. Detailed photophysical and circular dichroism (CD) studies have unveiled the crucial role of the solvent in the chiral aggregation of these NCDPs. NCDPs 1–3 form supramolecular helical assemblies and exhibit remarkable chiroptical switching behaviour (M‐ to P‐type) depending on the solvent composition of HFIP and DMSO. The strong influence of solvent composition on the supramolecular chirality of NCDPs has been further corroborated by concentration and solid‐state thin‐film CD studies. The chiroptical switching between supramolecular aggregates of opposite helicity (M and P) has been found to be reversible, and can be achieved through cycles of solvent removal and redissolution in solvent mixtures of specific composition. The control molecular systems (NCDPs 4–6), with an achiral or D‐isomer second amino acid in the CDP auxiliary, did not show chiral aggregation properties. The substantial roles of hydrogen bonding and π–π interactions in the assembly of the NCDPs have been validated through nuclear magnetic resonance (NMR), photophysical, and computational studies. Quantum chemical calculations at the ab initio, semiempirical, and density functional theory levels have been performed on model systems to understand the stabilities of the right (P‐) and left (M‐) handed helical supramolecular assemblies and the nature of the intermolecular interactions. This study emphasizes the role of CDP chiral auxiliaries on the solvent‐induced helical assembly and reversible chiroptical switching of naphthalenediimides.
ChemInform Abstract: The Tetragermanates A2Ge4O9 (A: Na, K and Rb).
Authors: Redhammer Guenther J. , Tippelt Gerold 
Published: November 2013

AbstractThe structures of the isotypic title compounds (trigonal, space group P$\bar 3$c1, Z = 6) are redetermined by single crystal XRD.
ChemInform Abstract: Optical and Structural Investigations on Sb2S2O New Kermesite Alloy for Optoelectronic Applications.
Authors: Lakhdar M. Haj , Larbi T. , Ouni B. , Amlouk M. 
Published: November 2013

AbstractSb2S2O thin films are prepared on glass substrates by heat treatment of vapor deposited Sb thin films (100 °C substrate temperature) both in sulfur atmosphere (300 °C, 6 h) and finally in air (350 °C, 6 h).
ChemInform Abstract: Bismuth Phosphate: A Novel Cathode Material Based on Conversion Reaction for Lithium‐Ion Batteries.
Authors: Hu Benan , Wang Xianyou , Wei Qiliang , Shu Hongbo , Yang Xiukang , Bai Yansong , Wu Hao , Song Yunfeng , Liu Li 
Published: November 2013

AbstractHexagonal BiPO4 is precipitated from a solution of Bi(NO3)3 in 10 wt.% aq.
ChemInform Abstract: Ca[LiAlN2]: A Quaternary Nitridoaluminate.
Authors: Pust Philipp , Pagano Sandro , Schnick Wolfgang 
Published: November 2013

AbstractCa[LiAlN2] is prepared by reaction of LiAlH4, LiN3, and Ca in a lithium flux (weld‐shut Ta crucibles in silica tube, 900 °C, 24 h).
ChemInform Abstract: Synthesis and Characterization of a Soluble Vanadium‐Containing Keggin Polyoxoniobate by ESI‐MS and 51V NMR: (TMA)9 [V3Nb12O42]·18H2O.
Authors: Son Jung‐Ho , Ohlin C. Andre , Larson Emma C. , Yu Ping , Casey William H. 
Published: November 2013

AbstractThe title compound (TMA: tetramethylammonium) is hydrothermally synthesized from a mixture of hydrous Nb2O5 and V2O5 in aqueous Me4NOH solution (autoclave, 110 °C, 86 h, 36% yield).
ChemInform Abstract: Dipotassium Diaquadiphosphatooctaperoxotetramolybdate, [K2(P2O7){MoO (O2)2}2 {MoO(O2)2(OH2)}2]2‐ — A One‐Dimensional Double Chain Array of Polyanions linked by Potassium Cations.
Authors: Aoki Koji , Iwata Keisuke , Iwata Takahiro , Hashimoto Masato 
Published: November 2013

AbstractThe title anion is synthesized by reaction of metallic molybdenum dissolved in H2O2, K4P2O7 and Me4NCl (H2O, 20 °C, 1—2 d; 69% yield).
ChemInform Abstract: Design and Evaluation of Improved Magnetic Stir Bars for Single‐Mode Microwave Reactors.
Authors: Obermayer David , Damm Markus , Kappe C. Oliver 
Published: November 2013

AbstractA new vertical blade stir bar that improves the stirring performance in flow‐constricting microwave vessels is designed and evaluated for several transformations where stirring and efficient agitation are known to be of importance.
ChemInform Abstract: Rhodium‐Catalyzed Highly Regioselective Hydroaminomethylation of Styrenes with Tetraphosphorus Ligands.
Authors: Li Shengkun , Huang Kexuan , Zhang Jiwen , Wu Wenjun , Zhang Xumu 
Published: November 2013

AbstractIn contrast to other known methods the linear products are predominantly formed by this procedure.
ChemInform Abstract: Highly Efficient Synthesis of Aryl and Heteroaryl Trifluoromethyl Ketones via o‐Iodobenzoic acid (IBX).
Authors: Cheng Huicheng , Pei Yu , Leng Faqiang , Li Jingya , Liang Apeng , Zou Dapeng , Wu Yangjie , Wu Yusheng 
Published: November 2013

AbstractThe coupling of aldehydes (I) and (V) with trimethyl(trifluoromethyl)silane (II) followed by deprotection of intermediate Tms‐protected alcohols affords trifluoromethylated alcohols (III) and (VI), which are readily oxidized with IBX to desired ketones (IV) and (VII) in high yields.
ChemInform Abstract: Methylene‐Bridged Bis(imidazoline)‐Derived 2‐Oxopyrimidinium Salts as Catalysts for Asymmetric Michael Reactions.
Authors: Sheshenev Andrey E. , Boltukhina Ekaterina V. , White Andew J. P. , Hii King Kuok 
Published: November 2013

AbstractA series of 2‐oxopyrimidinium chlorides is prepared and their utility as chiral catalyst for the asymmetric Michael reaction is demonstrated.
ChemInform Abstract: Synthesis of Functionalized Pseudopeptides Through Five‐Component Sequential Ugi/Nucleophilic Reaction of N‐Substituted 2‐Alkynamides with Hydrazides.
Authors: Maghari Shokoofeh , Ramezanpour Sorour , Balalaie Saeed , Darvish Fatemeh , Rominger Frank , Bijanzadeh Hamid Reza 
Published: November 2013

AbstractA novel approach for the synthesis of the title compounds containing hydrazones [e.g. (VI)] and vinyl hydrazide (XIV) groups is presented for a broad substrate scope.
ChemInform Abstract: Asymmetric Synthesis of Druglike Six‐Membered Spirooxindoles Through an Amino Enyne Catalysis.
Authors: Ramachary D. B. , Venkaiah Chintalapudi , Madhavachary R. 
Published: November 2013

AbstractA versatile new method for the room‐temperature synthesis of the title compounds is developed and uses a quinine‐derived organocatalyst.
ChemInform Abstract: Regioselective Ruthenium Catalyzed Hydrohydroxyalkylation of Dienes with 3‐Hydroxy‐2‐oxindoles: Prenylation, Geranylation, and Beyond.
Authors: Chen Te‐Yu , Krische Michael J. 
Published: November 2013

AbstractA Ru‐catalyst system is presented to allow unique alcohol dehydrogenation and subsequent diene‐carbonyl oxidative C‐C coupling.
ChemInform Abstract: Palladium‐Catalyzed Oxidative Cross‐Coupling of N‐Tosylhydrazones with Indoles: Synthesis of N‐Vinylindoles.
Authors: Zeng Xiaobao , Cheng Guolin , Shen Jinhai , Cui Xiuling 
Published: November 2013

AbstractThe novel title oxidative Pd‐catalyzed cross‐coupling reaction tolerating a wide scope of functional groups is developed.
ChemInform Abstract: Molecular Diversity of Cycloaddition Reactions of the Functionalized Pyridinium Salts with 3‐Phenacylideneoxindoles.
Authors: Fu Qin , Yan Chao‐Guo 
Published: November 2013

AbstractDeprotonation of pyridinium salts provides pyridinium ylides which undergo Michael addition/cyclization reaction with indole derivatives (I) to form spirocyclic compounds and furanylidene‐oxindoles.
ChemInform Abstract: A Novel Allylic Substitution Strategy to Four‐Component Synthesis of Pyrazole‐Substituted Fused Pyrroles.
Authors: Tu Xing‐Chao , Fan Wei , Jiang Bo , Wang Shu‐Liang , Tu Shu‐Jiang 
Published: November 2013

AbstractThe reaction time over two steps takes ca. 30 min in all cases.
ChemInform Abstract: Novel and Efficient Synthesis of 4,7‐Dihydro‐1H‐pyrrolo[2,3‐b]pyridine Derivatives via One‐Pot, Three‐Component Approach from N‐Substituted 5‐Amino‐3‐cyanopyrroles, Various Carbonyl and Active Methylene Compounds.
Authors: Vilches‐Herrera Marcelo , Spannenberg Anke , Langer Peter , Iaroshenko Viktor O. 
Published: November 2013

AbstractSimple procedures are presented for the synthesis of in total about 50 novel dihydropyrrolopyridines with fused 4‐spirocyclic frameworks under mild conditions.
ChemInform Abstract: Sequential Reactions of Trimethylsilyldiazomethane with 4‐Alkenyl Ketones and Aldehydes Catalyzed by Lewis Bases.
Authors: Liu Huaqing , O'Connor Matthew J. , Sun Chunrui , Wink Donald J. , Lee Daesung 
Published: November 2013

AbstractA wide range of novel bi‐ and tricyclic pyrazolines are synthesized via addition of trimethylsilyldiazomethane to aldehydes or ketones, 1,3‐Brook rearrangement, and intramolecular 1,3‐dipolar cycloaddition.
ChemInform Abstract: Reaction of Acylpyruvic Acid Esters with Hydrazides.
Authors: Pakal'nis V. V. , Zerova I. V. , Yakimovich S. I. , Alekseyev V. V. 
Published: November 2013

Abstract5‐Hydroxy‐2‐pyrazolines are obtained by reaction of hydrazides with acylpyruvic acid esters possessing a terminal straight chain alkyl substituent at the C=O bond distal from the ester group.
ChemInform Abstract: Synthesis, Characterization, and in vitro Antimicrobial Activity of Methyleneamine‐Linked Bis‐heterocycles.
Authors: Babulreddy A. , Hymavathi R. V. , Hussain Md. Manzoor , Swamy G. Narayana 
Published: November 2013

AbstractProducts (III) exhibit antimicrobial activity.
ChemInform Abstract: Synthesis and Biological Evaluation of Some New Polyfluorinated 4‐Thiazolidinone and α‐Aminophosphonic Acid Derivatives.
Authors: Abdel‐Rahman Reda M. , Ali Tarik E. 
Published: November 2013

AbstractAll synthesized compounds are screened for their antifungal activity against Alternaria alternate and Fusarium oxysporium and the enzymatic effects of the cellobiase produced by the fungi are estimated.
ChemInform Abstract: The Inhibitory Effect of a Synthetic Compound, (Z)‐5‐(2,4‐Dihydroxybenzylidene)thiazolidine‐2,4‐dione (MHY498), on Nitric Oxide‐Induced Melanogenesis.
Authors: Chung Hae Young , et al. et al. 
Published: November 2013

AbstractMHY498 (III) is found to be a promising anti‐melanogenic agent.
ChemInform Abstract: Synthesis of 2,4,5‐Trisubstituted Thiazoles via Lawesson′s Reagent‐Mediated Chemoselective Thionation‐Cyclization of Functionalized Enamides.
Authors: Kumar S. Vijay , Parameshwarappa G. , Ila H. 
Published: November 2013

AbstractEnamides obtained by ring‐opening of oxazoles either with sodium alkoxides or primary amines, efficiently undergo the title reaction in the presence of Lawesson reagent.
ChemInform Abstract: A Recyclable Ruthenium(II) Complex Supported on Magnetic Nanoparticles: A Regioselective Catalyst for Alkyne—Azide Cycloaddition.
Authors: Wang Dong , Salmon Lionel , Ruiz Jaime , Astruc Didier 
Published: November 2013

AbstractA magnetically separable Ru‐catalyst is synthesized through immobilizing a pentamethylcyclopentadienyl Ru‐complex on maghemite nanoparticles.
ChemInform Abstract: One‐Pot Preparation of 3‐Chloropiperidine Compounds via Cu(II)‐Promoted Intramolecular Chloroamination of Unfunctionalized Olefins.
Authors: Li Run‐Lin , Liu Gong‐Qing , Li Wei , Wang Yu‐Mei , Li Lin , Duan Lili , Li Yue‐Ming 
Published: November 2013

AbstractThe CuCl2 promoted cyclization of unsaturated amines at room temperature leads to the formation of intermediate pyrrolidine derivatives, which rearrange at elevated temperature to produce piperidines.
ChemInform Abstract: Design, Synthesis, Biological Evaluation, and Molecular Docking Studies of Quinolone Derivatives as Potential Antitumor Topoisomerase I Inhibitors.
Authors: Shou Kai‐jun , Li Jie , Jin Yi , Lv Yan‐wen 
Published: November 2013

AbstractN‐substituted piperazinylquinolone derivatives (I) are prepared via a two‐step one‐pot tandem process by reaction of arylsulfonyl chloride with cyanamide and subsequent addition of norfloxacin or ciprofloxacin hydrochloride.
ChemInform Abstract: Novel Synthetic 9‐Benzyloxyacridine Analogue as Both Tyrosine Kinase and Topoisomeras I Inhibitor.
Authors: Lang Xu‐Liang , Sun Qin‐Sheng , Chen Yu‐Zong , Li Lu‐Lu , Tan Chun‐Yan , Liu Hong‐Xia , Gao Chun‐Mei , Jiang Yu‐Yang 
Published: November 2013

AbstractA series of novel 9‐benzylaminoacridine derivatives (III) and their analogue 9‐benzyloxyacridine (V) are synthesized.
ChemInform Abstract: Synthesis of Benzopyranopyrrolidines via 1,3‐Dipolar Cycloaddition of Nonstabilized Azomethine Ylides with 3‐Substituted Coumarins.
Authors: Moshkin Vladimir S. , Sosnovskikh Vyacheslav Ya. , Roeschenthaler Gerd‐Volker 
Published: November 2013

AbstractAzomethine ylides generated in situ from amino acids and aldehydes or ketones undergo 1,3‐dipolar cycloadditions with coumarine derivatives to afford benzopyranopyrrolidines.
ChemInform Abstract: Highly Efficient Construction of Pentacyclic Benzo[b]indeno‐[1,2,3‐de][1,8]naphthyridine Derivatives via Four‐Component Domino Reaction.
Authors: Cao Cheng‐Pao , Lin Wei , Hu Ming‐Hua , Huang Zhi‐Bin , Shi Da‐Qing 
Published: November 2013

AbstractThe one‐pot transformation involves the formation of four new C—C and two new C—N bonds, as well as the construction of three new rings with efficient use of all reactants.
ChemInform Abstract: Synthesis and Properties of 6,6‐Di(indol‐3‐yl)indolo[2,1‐b]quinazolin‐12(6H)‐one and Its 2,8‐Dimethyl and 2,8‐Dibromo Derivatives.
Authors: Moskovkina T. V. , Kalinovskii A. I. , Martyyas E. A. , Anisimov M. M. 
Published: November 2013

AbstractThe new tryptanthrin derivative (IIIa) possesses moderate inhibitory activity to C.
ChemInform Abstract: Synthesis of Some New Nitrogen Bridge‐Head Triazolopyridines, Pyridotriazines, and Pyridotriazepines Incorporating 6‐Methylchromone Moiety.
Authors: Abdel‐Megid M. , Ibrahim M. A. , Gabr Y. , El‐Gohary N. M. , Mohamed E. A. 
Published: November 2013

AbstractAll products are purified by recrystallization.
ChemInform Abstract: Reaction of Strongly Electrophilic Alkenylboranes with Phosphanylalkynes: Rare Examples of Intermolecular 1,1‐Alkenylboration Reactions.
Authors: Ekkert Olga , Tuschewitzki Ottmar , Daniliuc Constantin G. , Kehr Gerald , Erker Gerhard 
Published: November 2013

AbstractThe title reaction affords phosphane‐borane Lewis pairs (III) with a conjugated diene backbone.
ChemInform Abstract: Synthesis of New (3‐Fluoroimidazo[1,2‐a]pyridin‐2‐yl)phosphonates
Authors: Aksinenko A. Yu. , Goreva T. V. , Epishina T. A. , Sokolov V. B. 
Published: November 2013

Abstractby a tandem reaction of imidoyl chlorides (III) with two equivalents of triethyl phosphite
ChemInform Abstract: Sesquiterpene Coumarins from Ferula fukanensis and Their Proinflammatory Cytokine Gene Expression Inhibitory Effects.
Authors: Motai Tsunetake , Daikonya Akihiro , Kitanaka Susumu 
Published: November 2013

AbstractSix novel sesquiterpene coumarin derivatives, fukanefuromarin H‐M, (I)‐(IV), are isolated from the roots of F.fukanensis.
ChemInform Abstract: Triterpenes with Cytotoxicity from the Leaves of Vernicia fordii.
Authors: Pei Yi‐Hua , Kwon Ok‐Kyoung , Lee Ji‐Seon , Cha Hyuk‐Jin , Ahn Kyung‐Seop , Oh Sei‐Ryang , Lee Hyeong‐Kyu , Chin Young‐Won 
Published: November 2013

AbstractNew triterpenes (I) and (II) are isolated from the title plant along with five known triterpenes.
ChemInform Abstract: Two New Bufotoxins from the Skin of Bufo bufo gargarizans
Authors: Li Hai‐Yan , Zhang Lian‐Zhu , Wang Shi‐Hui , Deng Yue , Jin Xiang‐Qun 
Published: November 2013

Abstractisolation and structure determination of two new bufotoxins, tolocinobufagin‐3‐succinoylarginine ester and tolocinobufagin‐3‐hemisuberate
ChemInform Abstract: A Facile One‐Pot Route for the General Synthesis of Triazole Linked Chiral 2‐Substituted Benzimidazoles.
Authors: Dutta Samrat , Sarkar Swarbhanu , Sen Asish Kumar 
Published: November 2013

AbstractThe fast and plain approach involves copper(I) catalyzed simultaneous formation of benzimidazole and triazole rings.
ChemInform Abstract: New Method of Isolation of Piperine from Piper retrofractum Vahl.
Authors: Pandey Archana , Gupta Ravindra Kumar , Srivastava Santosh Kumar , Agrawal Babita 
Published: November 2013

AbstractA new method for the isolation of piperine (I) from Piper retrofractum Vahl by methanol/water is described.
ChemInform Abstract: Directly Regioselective Protection of Secondary Hydroxyl Group on Ribosides in Aqueous Solution.
Authors: Xu Ruigang , Liu Fei , Liu Yingju , Chen Beiqing , Liu Feng‐Wu 
Published: November 2013

AbstractThe treatment with benzoyl chloride and Na2CO3 in aqueous acetonitrile allows regioselective benzoylation of secondary hydroxyl moieties in ribosides.
ChemInform Abstract: New Rotenoids and Coumaronochromonoids from the Aerial Part of Boerhaavia erecta.
Authors: Do Thi My Lien , Truong Anh Vu , Pinnock Travis George , Pratt Lawrence Michael , Yamamoto Shigeki , Watarai Hitoshi , Guillaume Dominique , Nguyen Kim Phi Phung 
Published: November 2013

AbstractTwo new coumaronochromanoids, (I) and (III), and three new rotenoids, (II), (IV), and (V), are isolated from the title plant, together with ten known compounds.
ChemInform Abstract: Synthetic Methods to Incorporate α‐Linked 2‐Amino‐2‐deoxy‐D‐glucopyranoside and 2‐Amino‐2‐deoxy‐D‐galactopyranoside Residues into Glycoconjugate Structures
Authors: Kerns Robert J. , Wei Peng 
Published: November 2013

AbstractReview: 74 refs.
ChemInform Abstract: Preparation and Use of Samarium Diiodide (SmI2) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction
Authors: Sadasivam Dhandapani V. , Choquette Kimberly A. , Flowers Robert A. 
Published: November 2013

AbstractReview: 28 refs.
Whose firm is it anyway? Analyzing ownership effects on IPO performance
Authors: Sur Sujit , Martens Martin L. 
Published: November 2013

AbstractThis study revisits current practice that ownership holding at IPO has a homogeneous impact on IPO performance. Using signalling theory, we develop and test a conceptual model explaining the relationships between the aggregated ownership structure and IPO price premium. We argue that aggregated ownership has a direct effect on issue price premium, and offer specific hypotheses on the effect of the shares sold during the offering by each type of owner on IPO performance. We use archival data from a sample of US firms that issued IPOs between 1996 and 2000 and find a significant direct effect of ownership configuration, namely, heterogeneity in effect of each ownership type on IPO performance as well as interaction effects between different ownership types. Copyright © 2013 ASAC. Published by John Wiley & Sons, Ltd.
Novel Donor‐Acceptor Copolymers Based on Dithienosilole and Ketone Modified Thieno[3,4‐b]thiophene for Photovoltaic Application
Authors: Chen Lie , Cai Shujiao , Wang Xianbo , Chen Yiwang 
Published: November 2013

AbstractTwo novel donor‐acceptor (D‐A) copolymers containing dithienosilole (DTS) donor unit and ketone modified thieno[3,4‐b]thiophene (TT) acceptor unit, namely, poly{4,4′‐bis(2‐ethylhexyl)dithieno[3,2‐b:2′,3′‐d]silole‐5,5′‐diyl‐alt‐1‐(thieno[3,4‐b]thiophen‐2‐yl)‐2‐ethylhexan‐1‐one} (PDTSTT) and poly{4,4′‐bis(2‐ethylhexyl)dithieno[3,2‐b:2′,3′‐d]silole‐5,5′‐diyl‐alt‐1‐(4,6‐bis(4‐ethylhexylthien‐2‐yl)thieno[3,4‐b]thiophen‐2‐yl)‐2‐ethylhexan‐1‐one} (PDTSDTTT), were synthesized for the application in polymer solar cells (PSCs), and the effects of thiophene bridge on the structural geometry and photovoiltaic performance have been investigated. The polymer PDTSTT and PDTSDTTT have the electrochemical bandgaps of 1.54 and 2.02 eV, together with low‐lying HOMO energy levels of −5.47 and −5.37 eV, respectively. Molecular geometry simulation result shows that compared with PDTSTT, the insertion of thiophene bridge in PDTSDTTT can well relieve the steric hindrance between the TT and DTS unit, as confirmed by the reduced dihedral angle between DTS and DTTT unit. Under the illumination of AM 1.5G, 100 mW/cm2, the PSC based on PDTSDTTT/PC61BM (1:1, w:w) demonstrates a power conversion efficiency of 1.0%, which is significantly improved in comparison with the device based on PDTSTT/PC61BM (1:2, w:w) under the same experimental condition. This is because the enhanced planarity and increased effective conjugation of the main chain in PDTSDTTT promote the more favorable morphology for charge transportation, although PDTSTT possesses the broader absorption band than PDTSDTTT.
Organic Fluorescent Molecule with High Solid State Luminescent Efficiency and Protonation Stimuli‐response
Authors: Ma Suqian , Zhang Jibo , Chen Jinlong , Wang Lijuan , Xu Bin , Tian Wenjing 
Published: November 2013

AbstractA novel organic fluorophor with high solid state luminescent efficiency based on 1,4‐bis(2,2‐di(pyridin‐2‐yl)vinyl)benzene (BDP2VB) was designed and synthesized. It emits faintly in solution, but becomes a strong emitter in the aggregate state, demonstrating its aggregation induced emission (AIE) property. According to the crystal structure analysis, J‐type aggregation was formed in the packing mode of the molecule, which was demonstrated to be beneficial to gain high fluorescent quantum efficiency in solid state. Additionally, the emission color of BDP2VB can change dramatically in solid state as well as in solution by the protonation stimuli.
Square Planar Nickel(II) Complexes with Halogenated o‐Diiminobenzosemiquinonato Ligation: Synthesis, Characterization, and Redox Property
Authors: Zuo Wansheng , Zhang Long , Xie Meihua , Deng Liang 
Published: November 2013

AbstractSeven square planar bis(o‐diiminobenzosemiquinonato)nickel(II) complexes, [Ni(o‐C6H4(NH)(NAr))2] (Ar=Mes, 1; p‐F‐C6H4, 2; p‐Cl‐C6H4, 3), [Ni(o‐4,5‐F2‐C6H2(NH)(NPh))2] (4), and [Ni(o‐4,5‐Cl2‐C6H2(NH)(NAr))2] (Ar=Ph, 5; 2,6‐F2‐C6H3, 6; 2,6‐Cl2‐C6H3, 7), have been synthesized and characterized by 1H NMR, 13C NMR, 19F NMR, IR, UV‐Vis‐NIR, elemental analyses, HRMS, as well as single‐crystal X‐ray diffraction studies (1 and 7). The cyclic voltammograms of these complexes exhibit two reversible redox processes of [NiL2]0/1− and [NiL2]1−/2−, and one irreversible process of [NiL2]0/2+. Substituent effects on the redox properties of these complexes, in addition with those of the known complexes [Ni(o‐C6H4(NH)(NPh))2] (8) and [Ni(o‐3,5‐But2‐C6H2(NH)2)2] (9), are identified by comparing the half‐wave potentials of the reduction waves, as 1≈9<8≈2<3<4<5<7<6, reflecting the ease of reduction of [NiL2] parallels the electron‐donating and ‐withdrawing ability of the substituent group. Reduction of 1 with one or two equivalents of sodium metal in THF has led to the isolation of [Na(THF)3][1] and [Na(THF)3]2[1]. The structure data of these two complexes revealed by low‐temperature X‐ray crystallography suggest their corresponding electronic structures of [NiII(1L·1−)(1L2−)]1− and [NiII(1L2−)2]2−, which are in line with those of [9]n (n=1−, 2−) suggested by spectroelectrochemical study.