Synthesis and characterization of ultra-thin MgO films on Mo(100

of 5

Please download to get full document.

View again

All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
5 pages
0 downs
Synthesis and characterization of ultra-thin MgO films on Mo(100
  DaltonTransactions COMMUNICATION Cite this:  Dalton Trans. , 2013,  42 , 5242 Received 8th January 2013,Accepted 18th February 2013DOI: 10.1039/c3dt00060e Synthesis and characterization of ultrathin metalcoordination Prussian blue nanoribbons † Suping Bao, a Wangping Qin, a Qihua Wu, a Guodong Liang,* a,b Fangming Zhu a,b andQing Wu a,b Ultrathin metal coordination Prussian blue (PB) nanoribbons withtunable width have been successfully synthesized. The mor-phology and microstructure of PB nanoribbons are characterizedusing UV-vis, FT-IR, AFM, TEM and XRD. PB nanoribbons syn-thesized possess an ultrathin thickness of approximately 1 nmand narrow width. The width of PB ribbons can be tuned byvarying the chain length of polymeric precursors. The PB hybridnanoribbons synthesized exhibit enhanced thermal stability andelectrochemical activity. The merit of narrow and tunable widthas well as ultrathin thickness of PB hybrid nanoribbons alongwith enhanced thermal stability and electrochemical activitymakes them potentially useful in nano-devices, biosensors and soon. Introduction Intense endeavors have been devoted to the construction of metal coordination nanomaterials with varied morphologiesdue to their versatile properties including reversible redox activity, superior thermal stability, excellent mechanicalstrength and so on, which give rise to a wide range of potentialapplications in nano-devices. 1,2 Since Mann and coworkerssynthesized metal coordination nanocubes of Prussian blue(PB) in reverse microemulsions, 3 numerous approaches havebeen developed to regulate the morphology of PB. Talham andcoworkers have synthesized two-dimensional PB grids throughmetal coordination of an amphiphilic pentacyanoferratecomplex at the air –  water interface. 4 MacLachlan and coworkershave prepared PB nanoworms and nanocontainers by meansof self organization of the ferrate-containing diblock copoly-mers. 5 Mini-emulsion droplets have also been used tosynthesize hollow nanoparticles of PB. 6 More recently, PBnanoparticles with tunable sizes have been synthesized in thepresence of polymeric templates. 7,8 However, the synthesis of highly anisotropic PB nanomaterials has been rarely reported. 4 Nanoribbons featuring narrow and straight-edged stripesrepresent promising building blocks or connecting units forapplications in nano-devices due to their intriguing structure-related physical properties. 9  Although nanoribbons of anumber of inorganic or organic materials have been syn-thesized, including graphene nanoribbons prepared by ex-foliating graphite, 9 a unzipping of carbon nanotubes 9 b orchemical vapor deposition processes, 9 c metal oxide or sulfidenanoribbons by thermal evaporation and condensation proces-ses, 9 d  dithioperylene nanoribbons by solution processes  etc. , 9 e the preparation of nanoribbons with narrow width (<10 nm),in which quantum confinement and the edge e ff  ect are signifi-cant, remains challenging. 9   f   Polypeptides, as one of the most important components of proteins, are able to arrange into  α helix and  β  fold structures due to supramolecular interactionamong amino acid units. 10 Such highly anisotropic structureso ff  er a new opportunity for the achievement of nanoparticles with unique architectures. Herein, we report the synthesis of PB hybrid nanoribbons with ultrathin thickness and tunable width using a cyanoferrate modified polypeptide as the precur-sor. We demonstrate that the PB hybrid nanoribbons exhibit enhanced thermal stability and electrochemical activity. Results and discussion Synthesis of PB hybrid nanoribbons To synthesize PB hybrid nanoribbons, a 4-armed star poly-( γ -benzyl- L -glutamate) modified with NH 4 Na 2 [Fe( II )(CN) 5 -(4-(aminomethyl)pyridine)] (PBLG – Fe,  6 ) was used (synthesis,ESI † ). In a typical experiment, 50 mg PBLG – Fe was suspendedin 10 mL distilled water with the assistance of sonication toget a light green suspension. Upon addition of Fe 3+ aqueoussolution, the color of the suspension changed to light blue ina few minutes, suggesting the formation of PB. The color † Electronic supplementary information (ESI) available: AFM height images of PB hybrid nanoribbons and synthesis of PBLG – Fe. See DOI: 10.1039/c3dt00060e a  DSAPM Lab, Institute of Polymer Science, School of Chemistry and Chemical  Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China. E-mail:; Tel: +86-20-84114033 b  PCFM Lab, OFCM Institute, Sun Yat-Sen University, Guangzhou, 510275, P. R. China 5242  |  Dalton Trans. , 2013,  42 , 5242 – 5246 This journal is © The Royal Society of Chemistry 2013  change implies that the cyanoferrate complex is accessible toFe 3+ and is located on the surface of the PBLG – Fe assembly, which enables the subsequent coordination with Fe 3+ . UV-visresults revealed that addition of Fe 3+ led to the appearance of the absorbance band at 721 nm (Fig. 1), attributed to chargetransfer of Fe( II ) – CN – Fe( III ). 11 The intensity of the absorbanceband increased with increasing Fe 3+ amounts until molarequivalent Fe 3+  was added, illustrating that Fe 3+ is involved inthe coordination polymerization reaction. The FT-IR spectrumof PBLG – Fe showed an absorbance band at 2060 cm − 1 attribu-table to the C u N stretching vibration (Fig. 2). This bandshifted to 2078 cm − 1 after coordination polymerization due tothe formation of the Fe( II ) – CN – Fe( III ) bridge. 12 Morphology of PB hybrid nanoribbons The morphology of PB hybrid nanoribbons fabricated wascharacterized using tapping mode atomic force microscopy (AFM) and transmission electron microscopy (TEM). A typical AFM image revealing ribbon-like structures is shown in Fig. 3.Cross-sectional analysis illustrated that the thickness of PBhybrid nanoribbons was  ca.  1 nm and the width was 9.7 nm(Fig. S1, ESI † ). The thickness of PB hybrid nanoribbons wassimilar to that of a single PBLG layer sandwiched between twoPrussian blue monolayers. PBLG – Fe is amphiphilic. WhenPBLG – Fe self organizes in aqueous media, hydrophobic PBLGlayers are sandwiched between two hydrophilic ferrate layers.Subsequent coordination polymerization of the cyanoferratecomplex with Fe 3+ leads to the formation of tri-layered struc-tures consisting of a PBLG layer sandwiched between two PBmonolayers. Moreover, the width of PB hybrid nanoribbons was close to the chain length of fully extended PBLG – Fe macro-molecules, implying that PBLG macromolecules aligned per-pendicular to the long axes of the ribbons. A typical TEMimage of PB hybrid nanoribbons with widths of   ca.  10 nm isshown in Fig. 3. Some sets of parallel lines with the interlinedistance of   ca.  0.5 nm aligned perpendicular to the long axisof the ribbons were discerned in TEM images. The endeavor toobtain EDX elemental mapping was unsuccessful due to rapiddegradation of nanoribbons upon exposure to intense electronbeams, likely associated with the ultrathin thickness. EDX analysis confirmed the presence of iron in PB hybridnanoribbons. Microstructure of PB hybrid nanoribbons Polypeptides such as PBLG exhibit secondary structuresinduced by intramolecular and intermolecular hydrogenbonding in bulk or in solution. 10 The secondary structure of PBLG depending on its molar mass can be verified using FT-IR. The FT-IR spectrum of PBLG showed two distinct absor-bance bands at 1628 cm − 1 and 1529 cm − 1 (Fig. 2), being characteristic of   β  sheets with anti-parallel configuration,ascribed to the C v O and C – N stretching vibrations, respective-ly. 10 a These bands remained for PBLG – Fe and PB hybridnanoribbons, demonstrating that inclusion of the ferratecomplex and formation of PB did not change the secondary structure of the  β  sheets of PBLG.The microstructure of PBLG, PBLG – Fe and PB hybridnanoribbons was characterized by means of wide-angle X-ray di ff  raction (XRD), as shown in Fig. 4. Two distinct reflectionsat 2 θ   = 5.4° and 2 θ   = 18.7°, attributed to lamellar stacking of   β sheets 7 a and the intermolecular distance between adjacent macromolecules within individual  β  sheets, 7 d  respectively, were observed for PBLG. The reflection peak at 2 θ   = 5.4° ( d   =1.61 nm) for PBLG shifted to a lower angle 2 θ   = 5.3° ( d   =1.67 nm) for PBLG – Fe, revealing that substitution of the benzyl Fig. 2  FT-IR spectra for PBLG, PBLG – Fe and PB hybrid nanoribbons. Fig. 3  Tapping mode AFM image (a) with a size of 600 nm × 600 nm, TEMimage (b) of PB hybrid nanoribbons and EDX spectrum (c). Fig. 1  UV-vis spectra of PBLG – Fe aqueous solution with various amounts ofFe 3+ . The concentration of PBLG – Fe was 0.30 mg mL − 1 . Dalton Transactions Communication This journal is © The Royal Society of Chemistry 2013  Dalton Trans. , 2013,  42 , 5242 – 5246 |  5243  ester moiety with the bulky ferrate complex enlarged slightly the gallery distance of the  β  sheets of PBLG. In contrast, thispeak disappeared completely for PB hybrid nanoribbons, illus-trating irreversible delamination of stacked  β  sheets. Thisresult was in good agreement with the morphological analysis.Moreover, the di ff  raction peak at 2 θ   = 18.7° ( d   = 0.48 nm)remained for PBLG – Fe and PB hybrid nanoribbons, indicating that the intermolecular arrangement of PBLG (individual  β sheets) was retained. A broad  “ amorphous halo ”  at 2 θ   =  ∼ 23° was observed for all samples investigated, derived mainly fromthe long amorphous side-chains. Moreover, it was worthnoting that no reflection peaks from PB crystals were detectedfor PB hybrid nanoribbons, which implied that PB nanolayersin ribbons were amorphous, likely due to the ultrathin thick-ness of PB nanolayers. Understanding the formation of PB hybrid nanoribbons PBLG – Fe before sonication consisted of stacked  β  sheets, asrevealed by FT-IR and XRD results. PBLG – Fe can not be dis-persed in water even with vigorous stirring. When a PBLG – Feaqueous mixture was subjected to sonication for 10 min,PBLG – Fe aggregates disappeared and a homogeneous clearsolution was obtained. The morphology of PBLG – Fe after soni-cation was examined using TEM (Fig. S2, ESI † ). Ribbon-likestructures, rather than stacked sheets or lamellae, wereobserved. This showed that the stacked  β  sheets of PBLG – Fe were delaminated into ribbon-like structures during sonicationof the PBLG – Fe aqueous suspension. Hydrophobic pristinePBLG was unable to disperse in water even using high-powersonication for long durations. Consequently, incorporation of the ferrate complex into PBLG – Fe was crucial for the delamina-tion of stacked  β  sheets of PBLG and the resulting formationof nanoribbons. Two possible reasons account for the ferrate-incorporation induced delamination of PBLG – Fe: (1) inclusionof the bulky cyanoferrate complex enlarges the gallery distanceof the  β  sheets of PBLG – Fe, as verified by XRD measurement (Fig. 4); (2) electrostatic repulsion among the negatively-charged ferrate complex ions of the  β  sheets is helpful for thedelamination of stacked  β  sheets and the formation of nanoribbons.The PBLG – Fe aqueous suspension after sonication was not stable, and flocculation occurred if left to stand over 30 min. After coordination polymerization with Fe 3+ and forming PBhybrid nanoribbons, the suspension was stable over 3 days,revealing that the formation of PB layers improved the dis-persion of hybrid ribbons in aqueous media. Tuning width of PB hybrid nanoribbons PB hybrid nanoribbons consisted of PBLG – Fe macromoleculesaligned perpendicular to the long axes, as implied by morpho-logical analysis. This means that the width of the nanoribbonsis related to the chain length of PBLG – Fe, and the shorterchain length of PBLG – Fe must lead to narrower nanoribbons.This finding encouraged us to regulate the width of PB hybridnanoribbons by varying the chain length of the PBLG – Fe, which can be readily achieved by varying the monomer/initiator ratio in the PBLG synthesis process. We next synthesized PB hybrid nanoribbons with narrower width using PBLG – S – Fe with a decreased molar mass of 5.8 kg mol − 1 (synthesis, ESI † ). The typical AFM image and cross-sec-tional profile of nanoribbons (Fig. S3, ESI † ) showed that PBhybrid nanoribbons had a similar thickness of 1 nm and adecreased width of 6.1 nm, as expected. Thermal property of PB hybrid nanoribbons The thermal stability of PB hybrid nanoribbons was evaluatedusing thermogravimetric analysis (TGA) (Fig. 5). PBLG beganto decompose mainly at 250 °C with a maximum decompo-sition rate at 280 °C. Decomposition of PBLG almost ceasedabove 500 °C and PBLG lost 88% of its initial mass. However,PB hybrid nanoribbons only lost 20% of their initial mass evenat high temperature (500 °C), which indicated that PB hybridnanoribbons possessed significantly enhanced thermal stab-ility in contrast to PBLG. The possible reason is that sandwich-ing of PBLG layers between inorganic PB nanolayers restrictsthe mobility of PBLG macromolecules, which prevents radicalspecies produced during thermal decomposition from Fig. 4  X-ray di ff raction (XRD) curves of conventional PB, PBLG, PBLG – Fe and PBhybrid nanoribbons. Fig. 5  Thermogravimetric analysis traces of PBLG, PBLG – Fe and PB hybridnanoribbons under N 2 . Communication Dalton Transactions 5244  |  Dalton Trans. , 2013,  42 , 5242 – 5246 This journal is © The Royal Society of Chemistry 2013  propagating. Moreover, thermal insulating PB nanolayers areinclined to inhibit heat flow during degradation. Electrochemical behavior of PB hybrid nanoribbons The electrochemical behavior of PB hybrid nanoribbons wasmeasured by using cyclic voltammograms (CVs). A typical CV curve of conventional PB particles showed two sets of distinct redox pairs, located at   E  1/2  = 0.18 V with a peak separation of 25 mV and at   E  1/2  = 0.86 V with a peak separation of 45 mV (Fig. 6), ascribed to reversible Prussian white/Prussian blueand Berlin green (or Prussian yellow)/Prussian blue conver-sion, respectively. 13 Both the former and the latter redox pairs with peak separations of 33 mV and 56 mV, respectively, wereobserved for PB hybrid nanoribbons, demonstrating regularPB structures with homogeneous charge distribution throughPB layers. The redox peak separations of PB hybrid nano-ribbons, associated with the di ff  usion rates of redox species tothe electrode, were comparable to those of three-dimensional(3D) PB particles. This revealed that PB hybrid nanoribbonspossessed similar charge di ff  usion rates to 3D PB particles,despite the amorphous nature of PB layers and the low fractionof PB in hybrid ribbons. Conclusions In summary, metal coordination Prussian blue (PB) nano-ribbons with ultrathin thickness and tunable width were syn-thesized for the first time. PB hybrid nanoribbons consisted of a single PBLG layer with macromolecules aligned perpendicu-lar to the long axes of ribbons, sandwiched between two amor-phous PB nanolayers. TGA results illustrated that PB hybridnanoribbons exhibited enhanced thermal stability. CV resultsrevealed that PB hybrid nanoribbons were electrochemically active. The intriguing microstructure of PB hybridnanoribbons together with their structure-related enhancedproperties made them useful in nano-devices, biosensors andso on. Experimental section Synthesis of PB hybrid nanoribbons To synthesize PB hybrid nanoribbons, 50 mg PBLG – Fe (syn-thesis, ESI † ) was suspended in 10 mL distilled water with theassistance of sonication. To the PBLG – Fe suspension wasadded a 2 molar equivalent Fe(NO 3 ) 3  aqueous solution. Themixture was stirred for 12 h at room temperature. The result-ing solution was added dropwise to 100 mL cold methanol with stirring. The mixture was centrifuged and the top layer was decanted. The solid was rinsed with methanol (50 mL × 3)and dried in a vacuum at 40 °C overnight to give light bluepowders. Characterization  A field emission gun TEM microscope (JEM2010HR) equipped with an Oxford Instrument UTW ISIS EDX system was used tocharacterize the microstructure of PB hybrid nanoribbons. Theacceleration voltage was 200 kV. The sample was prepared by drying a drop of PB hybrid nanoribbon/water suspension on acarbon-coated copper grid. The specimen was directly observed without staining due to the presence of iron. Tapping mode AFM to investigate the three-dimensional morphology of PB nanoribbons was performed using a commercial atomicforce microscope (SPM-9500J3) with a silicon micro-cantilever(spring constant 30 N m − 1 and resonance frequency   ∼ 270kHz). The scan rate varied from 0.1 to 2.0 Hz to optimize theimage quality. X-ray di ff  raction (XRD) measurements were per-formed using an XRD di ff  ractometer (D-MAX 2200 VPC)equipped with Ni-filtered Cu K α  radiation, having a wavelengthof 0.154 nm. The di ff  ractometer was scanned in 2 θ   range from1.5° to 50° and the scan rate used was 1.2° min − 1 . The TGA curves were recorded using a NetzschTG-209 thermo-balancein a temperature range from 25 to 550 °C at a heating rate of 10 °C min − 1 under nitrogen. UV-vis spectroscopy data wereobtained by using a Hitachi U3500 at room temperature. FT-IR spectra were recorded using a Nicolet/Nexus 670 FT-IR spectro-photometer. Powder samples were mixed with KBr and thenpressed into pellets for FT-IR measurements. Cyclic voltamme-try was performed using a CHI-660D electrochemical analyzer(CH Instruments, Inc.) in a three electrode cell. Glassy carbon working electrodes with a diameter of 3 mm were polished with a slurry of 0.05  μ m alumina particles, sonicated andrinsed with ultrapure water. After drying under N 2 , the glassy carbon working electrodes were made hydrophilic by treating in oxygen plasma (1 Torr O 2 , 10 W) for 5 min. The cleaning process was repeated until no voltammetric features wereobserved in the range from  − 0.2 to 1.2 V ( vs.  Ag/AgCl) at thescan rate of 100 mV s − 1 in 0.1 M KCl solution. PB hybridnanoribbons/water suspension was deposited on freshly cleaned glassy carbon working electrodes. The solvent was Fig. 6  Cyclic voltammogram of PB hybrid nanoribbons and conventional PBparticles deposited on glassy carbon electrodes. In 0.1 M KCl solution, scan rate:50 mV min − 1 , under N 2 . Dalton Transactions Communication This journal is © The Royal Society of Chemistry 2013  Dalton Trans. , 2013,  42 , 5242 – 5246 |  5245  allowed to evaporate at room temperature overnight. 0.1 M KClsolution was used as a bu ff  er solution. To remove oxygen, thebu ff  er solution was degassed by bubbling N 2  for 40 min priorto CV measurements. Every sample was tested three times toobtain reproducible results. Acknowledgements Financial support in part from NSFC (21074151), the Guangz-hou Planning Project of Science and Technology (11C52050729), the One Hundred Talents Project of SunYat-Sen University, the SRF for ROCS and SEM, and the Hong Kong Scholar Program (XJ2011047) is gratefully acknowledged. Notes and references 1 P. A. Rupar, L. Chabanne, M. A. Winnik and I. Manners, Science , 2012,  337 , 559 – 562.2 ( a ) F. H. Schacher, P. A. Rupar and I. Manners,  Angew.Chem., Int. Ed. , 2012,  51 , 7898 – 7921; ( b ) R. Ahmed, A. Priimagi, C. F. J. Faul and I. Manners,  Adv. Mater. , 2012, 24 , 926 – 931; ( c ) J. B. Gilroy, S. K. Patra, J. M. Mitchels,M. A. Winnik and I. Manners,  Angew. Chem., Int. Ed. , 2011, 50 , 5851 – 5855.3 ( a ) S. Vaucher, M. Li and S. Mann,  Angew. Chem., Int. Ed. ,2000,  39 , 1793 – 1796; ( b ) S. Vaucher, J. Fielden, M. Li,E. Dujardin and S. Mann,  Nano Lett. , 2002,  2 , 225 – 229.4 J. T. Culp, J. H. Park, D. Stratakis, M. W. Meisel andD. R. Talham,  J. Am. Chem. Soc. , 2002,  124 , 10083 – 10090.5 ( a ) X. Roy, J. K. H. Hui, M. Rabnawaz, G. J. Liu andM. J. MacLachlan,  J. Am. Chem. Soc. , 2011,  133 , 8420 – 8423;( b ) X. Roy, J. K. H. Hui, M. Rabnawaz, G. J. Liu andM. J. MacLachlan,  Angew. Chem., Int. Ed. , 2011,  50 , 1597 – 1602.6 ( a ) R. McHale, N. Ghasdian, Y. B. Liu, M. B. Ward,N. S. Hondow, H. H. Wang, Y. Q. Miao, R. Brydson andX. S. Wang,  Chem. Commun. , 2010,  46 , 4574 – 4576;( b ) S. J. Ye, Y. B. Liu, S. J. Chen, S. Liang, R. McHale,N. Ghasdian, Y. Lu and X. S. Wang,  Chem. Commun. , 2011, 47 , 6831 – 6833; ( c ) G. D. Liang, J. T. Xu and X. S. Wang,  J. Am. Chem. Soc. , 2009,  131 , 5378 – 5379; ( d  ) Y. B. Liu andX. S. Wang,  Polym. Chem. , 2012,  3 , 2632 – 2639.7 ( a ) H. Ming, N. L. K. Torad, Y. D. Chiang, K. C. W. Wu andY. Yamauchi,  CrystEngComm , 2012,  14 , 3387 – 3396;( b ) M. Hu, S. Furukawa, R. Ohtani, H. Sukegawa,Y. Nemoto, J. Reboul, S. Kitagawa and Y. Yamauchi,  Angew.Chem., Int. Ed. , 2012,  51 , 984 – 988; ( c ) N. L. Torad, M. Hu,M. Imura, M. Naito and Y. Yamauchi,  J. Mater. Chem. ,2012,  22 , 18261 – 18267; ( d  ) M. Hu and Y. Yamauchi,  Chem. Asian J. , 2011,  6 , 2282 – 2286; ( e ) M. Hu, A. A. Belik,H. Sukegawa, Y. Nemoto, M. Imura and Y. Yamauchi, Chem. Asian J. , 2011,  6 , 3195 – 3199.8 ( a ) A. Tokarev, P. Agulhon, J. Long, F. Quignard,M. Robitzer, R. A. S. Ferreira, L. D. Carlos, J. Larionova,C. Guerin and Y. Guari,  J. Mater. Chem. , 2012,  22 , 20232 – 20242; ( b ) B. Folch, J. Larionova, Y. Guari, K. Molvinger,C. Luna, C. Sangregorio, C. Innocenti, A. Caneschi andC. Guerin,  Phys. Chem. Chem. Phys. , 2010,  12 , 12760 – 12770.9 ( a ) X. L. Li, X. R. Wang, L. Zhang, S. W. Lee and H. J. Dai, Science , 2008,  319 , 1229 – 1232; ( b ) D. V. Kosynkin, A. L. Higginbotham, A. Sinitskii, J. R. Lomeda, A. Dimiev,B. K. Price and J. M. Tour,  Nature , 2009,  458 , 872 – 876;( c ) W. Liu, B. L. Jackson, J. Zhu, C. Q. Miao, C. H. Chung,Y. J. Park, K. Sun, J. Woo and Y. H. Xie,  ACS Nano , 2010,  4 ,3927 – 3932; ( d  ) Y. Jiang, W. J. Zhang, J. S. Jie, X. M. Meng, J. A. Zapien and S. T. Lee,  Adv. Mater. , 2006,  18 , 1527 – 1532;( e ) W. Jiang, Y. Zhou, H. Geng, S. D. Jiang, S. K. Yan, W. P. Hu, Z. H. Wang, Z. G. Shuai and J. A. Pei,  J. Am.Chem. Soc. , 2011,  133 , 1 – 3; (  f  ) J. M. Cai, P. Ru ffi eux,R. Jaafar, M. Bieri, T. Braun, S. Blankenburg, M. Muoth, A. P. Seitsonen, M. Saleh, X. L. Feng, K. Mullen andR. Fasel,  Nature , 2010,  466 , 470 – 473.10 ( a ) P. Papadopoulos, G. Floudas, H. A. Klok, I. Schnell andT. Pakula,  Biomacromolecules , 2004,  5 , 81 – 91; ( b ) K. T. Kim,C. Park, C. Kim, M. A. Winnik and I. Manners,  Chem.Commun. , 2006, 1372 – 1374; ( c ) K. T. Kim, C. Park,G. W. M. Vandermeulen, D. A. Rider, C. Kim, M. A. Winnik and I. Manners,  Angew. Chem., Int. Ed. , 2005,  44 ,7964 – 7968; ( d  ) Y. C. Lin and S. W. Kuo,  J. Polym. Sci., Part  A: Polym. Chem. , 2011,  49 , 2127 – 2137.11 ( a ) F. Armand, H. Sakuragi and K. Tokumaru,  New J. Chem. ,1993,  17 , 351 – 356; ( b ) S. H. Toma, J. A. Bonacin, K. Arakiand H. E. Toma,  Eur. J. Inorg. Chem. , 2007, 3356 – 3364.12 ( a ) S. F. A. Kettle, E. Diana, E. Boccaleri andP. L. Stanghellini,  Inorg. Chem. , 2007,  46 , 2409 – 2416;( b ) S. Z. Zhan, D. Guo, X. Y. Zhang, C. X. Du, Y. Zhu andR. N. Yang,  Inorg. Chim. Acta , 2000,  298 , 57 – 62.13 A. A. Karyakin,  Electroanalysis , 2001,  13 , 813 – 819. Communication Dalton Transactions 5246  |  Dalton Trans. , 2013,  42 , 5242 – 5246 This journal is © The Royal Society of Chemistry 2013
Related Search
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks