bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ab initio Valence Bond Study on AB‐type Molecules. A Description for XH (X = Li, Be, B, C, N, O, F) and XF (X = Li, Be, B)
Authors: Xin‐Li Liao , Yi‐Rong Mo , Wei Wu , Qian‐Er Zhang 
Published: September 2010

AbstractAb initio valence bond method is employed to quantitatively study the concepts of ionic resonance energy and ionicity of a chemical bond in the cases of hydrides XH (X = Li, Be, B, C, N, O, F) and fluorides XF (X = Li, Be, B). By establishing the relationship between resonance and stability, and comparing the calculated ionicities with Pauling's earlier estimations in the above diatomic molecules, the merits of Pauling's classical resonance theory were demonstrated at the ab initio level.
Crystal Structure and Characterization of a Large Polyoxotungstate (NH4)21{La(H2O)5[Ni(H2O)]2As4W40O140}·53H2O
Authors: Gang‐Lin Xue , Bin Liu , Wen‐Liang Wang , Qian‐Ding Li , Ji‐Wu Wang , Da‐Qi Wang 
Published: September 2010

AbstractThe heteropolytungstate (NH4)21{La(H2O)5[Ni(H2O)]2As4W40O140}·53H2O is obtained by the reaction of Na27[NaAs4W40O140]· 60H2O with NiCl2·6H2O, La(NO3)3·6H2O and NH4Cl at pH‐4.5. The structure and chemical composition are determined by X‐ray diffraction analysis and elemental analysis. The crystal data and main structure refinement are a = 1.9551(3) nm, b = 2.4156(4) nm, c= 3.7068(6) nm, β = 91.505(3)°, V = 17.500 (5) nm3, monoclinic crystal system with space group P21/n, Z = 4, R1 = 0.0573, wR2 = 0.0717 [I >2<s̀(I)], R1, = 0.2463 and wR2 = 0.1199 (all data). [La(H2O)5] {Ni(H2O)}2AS4W40O140 has C2, symmetry. IR spectra of the ligand [NaAs4W40O140]27‐ and its three complexes were discussed.
An Integrated Theory of Adsorption and Partition Mechanism and Each Contribution to Solute Retention in Reversed Phase Liquid Chromatography
Authors: Xin‐Du Geng , Fred E Regnier 
Published: September 2010

AbstractWith the combination of the the stoichiometric displacement model for retention (SDM‐R) in reversed phase liquid chromatography (RPLC) and the stoichiometric displacement model for adsorption (SDM‐A) in physical chemistry, the total number of moles of the re‐solvated methanol of stationary phase side, nr, and that of solute side in the mobile phase, q, corresponding to one mole of the desorbing solute, were separately determined and referred as the characterization parameters of the contributions of the adsorption mechanism and partition mechanism to the solute retention, respectively. A chromatographic system of insulin, using mobile phase consisting of the pseudo‐homologue of alcohols (methanol, ethanol and 2‐propanol)‐water and trifluoroacetic add was employed. The maximum number of the methanol layers on the stationary phase surface was found to be 10.6, only 3 of which being valid in usual RPLC, traditionally referred as a volume process in partition mechanism. However, it still follows the SDM‐R. Both of q and nr of insulin were found not to be zero, indicating that the retention mechanism of insulin is a mixed mode of partition mechanism and adsorption mechanism. When methanol is used as the organic modifier, the ratio of q/nr was 1.13, indicating the contribution to insulin retention due to partition mechanism being a bit greater than that due to adsorption mechanism. A linear relationship between q, or nr and the carbon number of the pseudo‐homologue in the mobile phase was also found. As a methodology for investigating the retention mechanism retention and behaviors of biopolymers, a homologue of organic solvents as the organic modifier in mobile phase has also been explored.
Synthesis of Novel Quinazoline Derivatives as Antimicrobial Agents
Authors: Aly A. A. 
Published: September 2010

AbstractQuinazoline isothiocyanate 1 reacts with various nucleophiles (nitrogen nucleophiles, oxygen nucleophiles and sulphur nucleophiles) to afford heterocyclic systemes 2–13. Also, the [4 + 2] cycloaddition reaction of 1 with phenyl isocyanate, benzylidene aryl amine and cinnamic acid derivatives gave novel heterocyclic compounds 14–16. Moreover, the reaction of 1 with active methylene compounds under Michael reaction conditions also was investigated to yield 17 and 18 and it was found that all these reactions proceeded via isothiocyanate heterocyclization to furnish non‐condensed heterocyclic compounds. Some of the newly synthesized compounds were tested for their antimicrobial activities.
Synthesis of Mixed‐ring Zirconocene Complexes Containing Alkenyl Group and Ethylene Polymerization Catalyzed with Them
Authors: Yan‐Long Qian , Xian‐Miao Qian , Ji‐Ling Huang , Jun‐Quan Sun 
Published: September 2010

AbstractFour new mixed‐ring zirconium completes, [CH2 = CH(CH2)n ‐C5H4](RC5H4)ZrCl2 [n = l, R = CH3OCH2CH2(3); n = 2, R = CH3OCH2CH2 (4); n = 2, R=Me3Si (5); n = 2, R = allyl (6)], have been prepared by the reaction of CH2 = CH(CH2)n C5H4ZrCl3, DME[n = l (1); n = 2 (2)] with RC5H4Li. When activated with methylaluminoxane (MAO), the catalytic activities of the above complexes in ethylene polymerization were tested. Complexes 5 and 6 show high activities similar to Cp2ZrCl2. Introduction of methoxyethyl group into Cp‐ligand dramatically decreases the catalytic activities of complexes 3 and 4, which can be overcome by increasing the amount of MAO. For complex 5, the dependence of activity and molecular weight (Mη) on the Al/Zr ratio, the polymerization time (tP), polymerization temperature (TP) and the polymerization solvent volume (V) was investigated.
Synthesis and Insulin‐sensitizing Activity of a Series of 2‐Benzyl‐1,3‐dicarbonyl Derivatives
Authors: Lei Tang , Ying Leng , Huo‐Quan Wang , Ying Feng , Yu‐She Yang , Ru‐Yun Ji 
Published: September 2010

AbstractA series of 2‐benzyl‐1,3‐dicarbonyl derivatives was synthesized. Their insulin‐sensitizing activity was evaluated in 3T3‐L1 preadipocyte cells. Compounds 3, 26 and 27 were found to possess strong insulin‐sensitizing activity in vitro and were selected for further hypoglycemic evaluation in vivo.
3‐Mercaptopropionic Acid Capped Gold Nanoclusters: Quantized Capacitance in Aqueous Media
Authors: Di Li , Jing‐Hong Li 
Published: September 2010

Abstract3‐Mercaptopropionic add monolayer protected gold nanoclusters (MPA‐MPCs) were synthesized and characterized by transmission electron microscopy, UV‐Vis spectroscopy, X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The exact value of quantized double‐layer capacitance of MPCs in aqueous media was obtained by differential pulse voltammograms.
Synthesis, Spectroscopic Characterization and Antitumor Activity in vitro of Organometallo Substituted Polyoxotungstates (RM)3P2W15‐ On59 (RM=CpTi, CpZr, C4H7O2Sn or C5H9O2Sn)
Authors: Xiao‐Hong Wang , Jiang‐Hua He , Rong‐Chang Zhang , Jing‐Fu Liu 
Published: September 2010

AbstractTetrabutylammonium or potassium salts of organometallic derivatives of lacunary polyanion (RM)3P2W15Qn59‐ (RM = CpTl, CpZr, C4H7Q2Sn or C5H9C2Sn) have been prepared and structurally characterized by elemental analysis, IR, UV‐vis, 1H NMR and 183 W NMR spectroscopies. The title complexes exhibit antitumor activity in vitro.
Separation of Basic Drugs Using Pressurized Capillary Electrochromatography
Authors: Kai Zhang , Zhi‐Chao Zhang , Qin‐Sun Wang , Ru‐Yu Gao , Chao Yan , Chuan‐Yi Yao , Zheng‐Jin Jiang 
Published: September 2010

AbstractA novel pressurized capillary electrochromatography (PCEC) was developed to separate basic drugs on strong cation exchange (SCX) column. The separation result by using PCEC was better than that by using micro‐HPLC. The effects of electrical field and pressure on plate height and resolution were investigated. Influence of organic modifier, ionic strength and pH value of buffer on retention behavior were evaluated, and the separation mechanism was also discussed.
Study on Frequency Doubling Scattering and Second‐Order Scattering Spectra of Heparin‐Methylene Blue System
Authors: Shao‐Pu Liu , Hong‐Qun Luo , Nian‐Bing Li , Zhong‐Fang Liu 
Published: September 2010

AbstractBinding of heparin with methylene blue (MB) in pH 5.7 Britton‐Robinson buffer can result in a significant enhancement of frequency doubling scattering (FDS) and second‐order scattering (SOS). Their maximum scattering wavelengths (λmax) appear at 350 nm for EDS and 700 nm for SOS, respectively. The optimum conditions of the reaction, the influencing factors and the relationship between the two scattering intensities and the concentration of heparin have been investigated. The new methods for the determination of trace amounts of heparin based on the FDS and SOS methods have been developed, which exhibit high sensitivities. The detection limits of heparin are 4.36 ng/mL for the FDS method and 3.55 ng/mL for the SOS method, respectively. Both of the methods have fairly good selectivity and were applied to the determination of heparin in sodium heparinate injection samples with satisfactory results. Moreover, the relative mechanisms have also been discussed.
Solvothermal Synthesis and Crystal Structure of a Novel Inorganic‐Organic Hybrid Material, Fe2O(OH)(C5H4NCOO)SO4
Authors: Hong‐You Guo , Zeng‐He Li , Xiu‐Yan Li , Chang‐Yuan Zhang , Ru‐Ji Wang 
Published: September 2010

AbstractA novel inorganic‐organic hybrid material, Fe2O(OH)(C5H4‐NCOO)SO4 was synthesized via solvothermal route using a reaction of FeCl3 ·6H2O, KCNS, and 4‐cyanopyridne in aqueous solution of H2O2 and ethanol at 130 °C for 3 d. The compound crystallized in monoclinic space group P21, with cell parameters a=0.73850(15) nm, b = 0.65100(13) mn, c = 1.0546(2) nm, β = 90.36(3)°, V = 0.50700(18) nm3 and Z = 2. The structure is constructed with inorganic layered [Fe2O(OH) SO4]+ cations linked by organic (C5H4NCOO)− anions. The compound is thermally stable up to approximately 240 °C.
Stereoselective Synthesis of (E)‐ and (Z)‐1,2‐Disubstituted Ethene from Polymer‐Supported Vinylic Selenide
Authors: Shou‐Ri Sheng , Xian Huang 
Published: September 2010

AbstractThis letter describes a method for the stereoselective synthesis of polymer‐supported vinylic selenides and their applications to synthesis of (E)‐ and (Z)‐1,2‐disubstituted ethenes on solid‐phase by the coupling reaction with Grignard reagents under the catalysis of NiCl2(PPh3)2.
Design and Theoretical Study of Nickel Catalysts for Syndiotactic Polyolefins
Authors: Ying Liu , Yue Liu , Jia‐Wen Liu , Michael Drew G. B. 
Published: September 2010

AbstractA nickel catalyst was modeled with ligand L2, [NH = CH—CH = CH—O]−, which should have potential use as a syndiotactic polyolefin catalyst, and the reaction mechanism was studied by theoretical calculations using the density functional method at the B3LYP/ LANL2MB level. The mechanism involves the formation of the intermediate [NiL2Me]+, in which the metal occupies a T‐shaped geometry. This intermediate has two possible structures with the methyl group trans either to the oxygen or to the nitrogen atom of L2. The results show that both structures can lead to the desired product via similar reaction paths, A and B. Thus, the polymerization could be considered as taking place either with the alkyl group occupying the position trans to the Ni—O or trans to the Ni—N bond in the catalyst. The polymerization process thus favors the catalysis of syndiotactic polyolefins. The syndiotactic synthesis effects could also be enhanced by variations in the ligand sub‐stituents. From energy considerations, we can conclude that it is more favorable for the methyl group to occupy the trans‐O position to form a complex than to occupy the trans‐N position. From bond length considerations, it is also more favoured for ethene to occupy the trans‐O position than to occupy the trans‐N position.
Crystal Structures and Magnetic Studies of Naphthalene Derivatives Containing Nitronyl Nitroxides
Authors: De‐Qing Zhang , Hong‐Qing Zhu , Liang Ding , Wei Xu , Wei Liu , Dao‐Ben Zhu 
Published: September 2010

AbstractCrystal structures of new nitronyl nitroxide derivatives 1, 2 and 3 were determined with X‐ray diffraction analysis: 1, monoclinic, C2/c, a = 1.2404(5) nm, b = 0.9730(5) um, c = 2.7049(10) ran, β = 98.189(15)°, V = 3.2315(24) nm3, Z = 8; 2, or‐thorhombic, Pbca, a = 0.61262(2) nm, b = 1.11426(6) nm, c = 2.30543(13) nm, V = 1.57373(13) nm3, Z = 4; 3, monoclinic, P2(1)/n, a=0.64253(4) nm, b=2.55003(17) nm, c = 1.15497(6) nm, β = 95.000(3)°, V = 1.8852(2) nm3, Z = 4. Their magnetic properties were measured with SQUID and analyzed based on their crystal structures with simple singlet‐triplet, modified one dimensional antiferromagnetic chain and modified singlet‐triplet models respectively: 1, J/kb= −2.5 K; 2, J/kb = 7.8 K, θ = 2.8 K; 3, J/kb = −0.96 K, θ = 0.21 K.
Zn2+ Recognition by Two New Bipyridine Ligands
Authors: Lin‐Qing Song , Yuan‐Jun Hou , Xue‐Song Wang , Bao‐Wen Zhang , Pu‐Hui Xie , Chang‐Qi Ma , Yi Cao 
Published: September 2010

AbstractTwo new bipyridine ligands with intramolecular charge transfer (ICT) transition as the lowest excited state were designed and synthesized. Upon addition of metal ions, particularly Zn2+, the absorption and emission spectra experience great changes. The binding constants towards Zn2+ are 1.27 × 105 L/mol and 1.66 × 105 L/mol for ligands 1 and 2, respectively. The strong binding affinity and high selectivity make them attractive for application as fluorescence sensors for Zn2+.
Syntheses, Characterization and Equilibrium between Mono‐and Aqua‐bridged Dicobalt(II) Complexes. A Structural Model for Methionine Aminopeptidase
Authors: Bao‐Hui Ye , Xiao‐Ming Chen 
Published: September 2010

AbstractA monomeric complex [Co(Im)2(O2CMe)2] (1) and a novel aquabridged dimeric complex [Co2(μ‐H2O)(μ‐CMe)2(Im)4‐(O2CMe)2] (2) (Im = imidazole) have been synthesized and characterized. Complexes 1 and 2 coexisted in solution. Pure forms of either complex can be obtained from the same solution by controlling the crystallization conditions. All two complexes possess a carboxylate‐Im‐cobalt(II) triad system analogous to the carboxylate‐histidine‐metal triad systems that have been found in many zinc enzymes and cobalt(II)‐substituted enzymes. In 2, two Co2+ ions are connected by a water molecule in a bridging fashion with Co°Co [0.3687(1) nm], Co—OH2 [0.2159(3) nm], and Co‐OH2‐Co [117.2(3)°], in which the water molecule is further stabilized by two intramolecular hydrogen bonds with the oxygens of the terminal monodentate acetate groups with the distance of O…0 [0.2609(7) nm]. The terminal monodentate acetate groups display quite abnormal geometry due to the strong “pulling effect” on the carboxylates by intermolecular and intramolecular hydrogen bonds. Complex 2 showed weak antiferromagnetic coupling at low temperature with g = 2.22 and J = −1.60 cm−1.
Cluster‐cracking Reaction, a New Method to Synthesize Unsymmetrical Dithiolate Complexes for the Study of Third‐Order Nonlinear Optical Properties
Authors: Guo‐Qmg Bian , Qin‐Yu Zhu , Xin Wang , Wei Yang , Ze‐Min Yan , Jie Dai , Zhen‐Rong Sun , Megumu Munakata , Masahiko Maekawa 
Published: September 2010

AbstractA new cluster‐cracking method to synthesize dithiolate metal complexes was reported and four unsymmetric complexes with formula (Me4N)2[M(Ln)(SPh)2] (M = Cd and Zn, L1 = dmit = 1,3‐dithiole‐2‐thione‐4, 5‐dithiolate, L2 = dmid = 1, 3‐dithiole‐2‐one‐4, 5‐dithiolate, SPh= thiophenolate) (1–4) were characterized by elemental analysis, IR, UV NMR spectra and so on. The advantages of this method are summarized in two aspects: (1) the preparation is very convenient; (2) the reaction usually completed giving the product with high purity. The crystal structure of 1 showed that the bond distances of Cd(II) to the sulfur of the thiophenolate group are shorter than those of Cd(II) to the sulfur of dmit, so that the thiophenolate group does not be replaced in the reaction and the mixed ligand complexes are the dominant products. The dmit complexes showed well third‐order NLO properties, but not of the dmid complexes, although dmid is an analogue to dmit.
Synthesis of New Chiral Building Blocks for Novel Peptide Nucleic Acids
Authors: Jie Wu , Xiao‐Yu Xu , Ke‐Liang Liu 
Published: September 2010

AbstractN‐Boc protected amino acids of analogues of peptide nucleic add (PNA.), which are a class of conformationally constrained building blocks based on 4‐aminoproline backbone with chirality at 2‐C and 4‐C, have been synthesized. Those monomers can be used for the construction of novel peptide nucleic acid analogues.
Lanthanide Complexes for Oligomerization of Phenyl Isocyanate
Authors: Ming‐Yu Deng , Ying‐Ming Yao , Yu‐Fang Zhou , Li‐Fen Zhang , Qi Shen 
Published: September 2010

AbstractA series of lanthanide complexes including (Ind)3Sm(THF) (1), [(MeCp)2Sm(μ‐SPh)(THF)]2(2), [(MeCp)2Y(μ‐O‐i‐Pr)]2 (3), (MeCp)3Sm·θF (4), Sm(SPh)3(hmpa)3(5), [(MeCp)2Y‐(μ‐OCH2CF3)]2(6) and (OF3CH2O)3 Y(THF)3 (7) were synthesized and they have good activity for the oligomerization of phenyl isocyanate. Among them 5 shows the highest activity. The conversion is as high as 96.2%, with 1/2500 of the molar ratio of cat./ PhNCO. The main components in oligomer were characterized to be a cyclodimer and a cyclotrimer. The ratio of cyclodimer to cyclotrimer depends on the lanthanide complexes used. 7 gave 85.2% cyclotrimer with 1/300 of the molar ratio of cat./PhNCO at 40 °C for 0.5 h, while 5 gave 77.6% cyclodimer with 1/300 of the molar ratio of cat./PhNCO at 40 °C for 4 h.
A New Solution‐phase Parallel Synthesis of 2‐Alkylamino‐3‐aryl‐5‐phenylmethylene‐3,5‐dihydro‐4H‐imidazol‐4‐ones
Authors: Ming‐Wu Ding , Yong Sun , Xiao‐Peng Liu , Zhao‐Jie Liu 
Published: September 2010

AbstractThirteen new 2‐alkylaminoimidazolones (4) were rapidly synthesized by a new solution‐phase parallel synthetic method, which includes aza‐Wittig reaction of iminophosphorane (1) with aromatic iso‐cyanate to give carbodi‐imide (2) and subsequent reaction of 2 with various aliphatic primary amine in a parallel fashion. The products were confirmed by 1H NMR, MS, IR and X‐ray crystallographic analysis. The unusual selectivity of the cyclization was probably due to the geometry of the guanidine intermediate.
Synthesis and Crystal Structure of a Novel Supramolecular Compound [Mg(H2O)6](C16H11O4SO3)2·10H2O
Authors: Zun‐Ting Zhang , Bo‐Lun Yang , Qian‐Guang Liu , Xiao‐Hong Liu , Zi‐Wd Gao , Kai‐Bei Yu 
Published: September 2010

AbstractA hydrolyte of magnesium 7‐methoxyl‐4′‐hydroxylisoflavone‐3′‐sulfonate ([Mg(H2O)6](C16H11O4SO3)2·10H2O) was synthesized and its crystal structure was determined by X‐ray diffraction analyses. The crystal belongs to triclinic crystal system, space group P‐1with cell constantsa= 0.7359(1) nm,b= 0.9935(1) nm,c= 1.6335(2) nm, α = 91.16(1)°, β = 92.07(1)°, γ = 106.53(1)°,V= 1.1436(2) nm5and Z = 1. The results show that the title compound consists of [Mg(H2O)6]2+, C16H11O4SO3‐and H2O. Mg(II) is located at the symmetry center of the title compound. [Mg(H2O)6]2+, C16H11SO3−and H2O form fourteen kinds of hydrogen bonds. The distance of 0.351 nm between parallel isoflavone rings shows a #‐# stacking interaction. The hydrogen bonds and #‐# stacking interaction lead to supramolecular formation with three‐dimensional network structure. The title compound was also characterized by IR and1H NMR spectra.
Unexpected Strong Luminescence of Polysiloxanes Containing Carbazolyl and C60 Moeities as Side Chains
Authors: Zhen Li , Jin‐Gui Qin , Yong Cao , Yu‐Hoa Niu 
Published: September 2010

AbstractTwo types of polysiloxanes, which contain both C60 moieties and carbazolyl groups in the side chains with a difference in the numbers of the reacting site on C60 molecules, were synthesized and their fluorescent properties were studied to distinguish the role of C60 in the luminescent polymers. Our results demonstrated that when C60 moieties are bonded to the polymers as multisubstituents but not linked to the luminescent moieties directly, the luminescence of the resultant polymers were still very strong instead of quenching, even the substituted degree is only 1.01.
Calculations on the Nonlinear Second‐Order Optical Polarizabilities for Series of Donor‐C60 Molecules
Authors: Xiao‐Juan Liu , Ji‐Kang Feng , Ai‐Min Ren , Xin Zhou 
Published: September 2010

AbstractThe equilibrium geometries and UV‐visible spectra of a series of donor‐C60 molecules were obtained by means of the AM1 and INDO/CI method, on the basis of accurate geometric and electronic structures. The nonlinear second‐order optical polarizabilities were calculated using the method INDO/SDCI combined with the Sum‐Over‐States (SOS) expression. The calculated β (λ=1.34μm) values are 28.81, 48.56, 57.33, 66.99, 70.85, 85.84, and 142.14 (× 10–30 esu) for the molecules A, B, C, D, E, F and G, respectively. The frontier orbitals were plot for the representative molecules in order to exhibit the intramolecular charge transfer. The results indicate that introduction of thienylethylene can enhance the NLO response and the dimethylaniline‐substituted dithienyl‐ethylene‐C60(molecule G) possesses the largest NLO second‐order optical polarizability. The large β values can be attributed to the charge transfer between the substituents and C60, as well as within the three‐dimensional conjugated sphere of C60.
Synthesis and Nonlinear Optical Characterization of a New Two‐photon Absorbing Organic Dye: DMAHAS
Authors: Yun‐Xing Yan , Dong Wang , Xian Zhao , Xu‐Tang Tao , Min‐Hua Jiang 
Published: September 2010

AbstractTrans‐4‐(N, N'‐dimethyl amino)‐4′‐(N‐hydroxyethyl‐N'‐ethyl amino) stilbene (DMAHAS) has been synthesized and characterized by 1H NMR spectra, ER spectra and elemental analysis. Linear absorption, single‐photon induced fluorescence and two‐photon induced fluorescence were experimentally studied. This new dye has a moderate two‐photon absorption cross‐section of σ 2 = 0.91 × 10–46 cm4 · s/photon at 532 nm by using an open aperture Z‐scan technique. The result indicates that DMAHAS shows a strong two‐photon induced blue fluorescence of 432 nm when pumped with 800 nm laser irradiation.
Investigation on the Electrochemical Polymerization of Catechol by Means of Rotating Ring‐disk Electrode
Authors: Yong Kong , Shao‐Lin Müu 
Published: September 2010

AbstractThe electrolysis of catechol was studied in the pH values of 1 to 10. The results from the rotating ring‐disk electrode (RRDE) experiments show that at low pH values, the electrochemical polymerization of catechol was performed by one step, and at higher pH values, the electrochemical polymerization of catechol was carried out by two steps, i.e. oxidation of catechol and followed by polymerization. The intermediates generated at the disk were detected at the ring electrode in the ring potential region of‐0.2to 0 V (vs. Ag/AgCl). One of reasons for the decrease in the ratio of ir to id with increasing the ring potential is caused by formation of positively charged intermediates at the disk electrode. This ratio increases with increasing the rotation rate of the RRDE, which indicates that the intermediates are not stable. A shielding effect during polymerization of catechol was observed when the ring potential was set at 0.1 V (vs. Ag/AgCl). The electron spin resonance (ESR) of polycatechol shows that polycatechol possesses unpaired electrons. The images of polycatechol films synthesized at different conditions are described.