Black-to-Transmissive Electrochromism with Visible-to-Near-Infrared Switching of a Co(II)-Based Metallo-Supramolecular Polymer for Smart Window and Digital Signage Applications.

Black-to-transmissive electrochromism has been obtained with a Co(II)-based metallo-supramolecular polymer (polyCo). Thin films of polyCo, based on bisterpyridine ligand assembled with Co(II) metal ion, were constructed by spray casting the polymer onto ITO glass. With such simple fabricating means to form good-quality films, polyCo films show stable switching at the central metal ion of the Co(II)/Co(I) redox reaction when immersed in aqueous solution. With an increase in the pH of the aqueous electrolyte solution from neutral, the film exhibits a color response due to the interaction between the d-orbital electron and hydroxide ions affecting the d-d* transition. As a result, a nearly transparent-to-black electrochromic performance can be achieved with a transmittance difference at 550 nm of 74.3% (81.9-7.6%) in pH 13 solution. The light absorption of the film can be tuned over light regions from visible to near-infrared with a large attenuation.

[1]  Justin R. Kumpfer,et al.  Optically healable supramolecular polymers , 2011, Nature.

[2]  A. Lledós,et al.  Neutral transition metal hydrides as acids in hydrogen bonding and proton transfer: media polarity and specific solvation effects. , 2010, Journal of the American Chemical Society.

[3]  Martin D Hager,et al.  Functional soft materials from metallopolymers and metallosupramolecular polymers. , 2011, Nature materials.

[4]  M. Higuchi,et al.  Metallosupramolecular polyelectrolytes self-assembled from various pyridine ring-substituted bisterpyridines and metal ions: photophysical, electrochemical, and electrochromic properties. , 2008, Journal of the American Chemical Society.

[5]  J. Périchon,et al.  Unexpected stabilization of a simple cobalt(I) salt in acetonitrile at a glassy carbon electrode , 2006 .

[6]  Peter Day,et al.  Mixed Valence Chemistry-A Survey and Classification , 1968 .

[7]  John R. Platt,et al.  Electrochromism, a Possible Change of Color Producible in Dyes by an Electric Field , 1961 .

[8]  H. Sigel,et al.  Influence of decreasing solvent polarity (1,4-dioxane/water mixtures) on the stability and structure of complexes formed by copper(II), 2,2′-bipyridine or 1,10-phenanthroline and guanosine 5′-diphosphate: evaluation of isomeric equilibria , 2009 .

[9]  D. Schlettwein,et al.  Switching of the Rate-limiting Step in the Electrochromic Reduction of Fluorinated Phthalocyanine Thin Films by Decreased Intermolecular Coupling , 2015 .

[10]  C. M. Elliott,et al.  A Series of Multicolor Electrochromic Ruthenium(II) Trisbipyridine Complexes: Synthesis and Electrochemistry , 1999 .

[11]  David R. Rosseinsky,et al.  Electrochromism and Electrochromic Devices , 2007 .

[12]  O. Reynes,et al.  Electrocarboxylation of chloroacetonitrile by a Cobalt(I) complex of terpyridine , 2011 .

[13]  S. Rowan,et al.  Using the dynamic bond to access macroscopically responsive structurally dynamic polymers. , 2011, Nature materials.

[14]  M. Higuchi,et al.  Stepwise radial complexation of imine groups in phenylazomethine dendrimers , 2002, Nature.

[15]  Andrew P. Meacham,et al.  A near-infrared electrochromic window based on an Sb-doped SnO2 electrode modified with a Ru-dioxolene complex. , 2003, Angewandte Chemie.

[16]  K. Swider-Lyons,et al.  Organometallic Supramolecular Mixed-Valence Cobalt(I)/Cobalt(II) Aquo Complexes Stabilized with the Water-Soluble Phosphine Ligand p-TPPTP (p-triphenylphosphine triphosphonic acid) , 2007 .

[17]  A. Cihaner,et al.  A new soluble neutral state black electrochromic copolymer via a donor-acceptor approach , 2010 .

[18]  Hung-Ju Yen,et al.  Transmissive to black electrochromic aramids with high near-infrared and multicolor electrochromism based on electroactive tetraphenylbenzidine units , 2011 .

[19]  B. Brunschwig,et al.  HOMOGENEOUS CATALYSIS OF THE PHOTOREDUCTION OF WATER BY VISIBLE LIGHT. MEDIATION BY A TRIS(2,2′‐BIPYRIDINE)RUTHENIUM(II)‐COBALT(II) MACROCYCLE SYSTEM , 1979 .

[20]  H. Nishihara,et al.  Electrochromic bis(terpyridine)metal complex nanosheets. , 2015, Journal of the American Chemical Society.

[21]  B. Brunschwig,et al.  Homogeneous catalysis of the photoreduction of water by visible light. Mediation by a tris(2,2'-bipyridine)ruthenium(II)-cobalt(II) macrocycle system , 1979 .

[22]  David Y. Liu,et al.  Broadly Absorbing Black to Transmissive Switching Electrochromic Polymers , 2010, Advanced materials.

[23]  M. Higuchi,et al.  Multi-colour electrochromic properties of Fe/Ru-based bimetallo-supramolecular polymers , 2013 .

[24]  A. Merbach,et al.  .pi.-Arene Aqua Complexes of Cobalt, Rhodium, Iridium, and Ruthenium: Preparation, Structure, and Kinetics of Water Exchange and Water Substitution , 1995 .

[25]  T. Meyer,et al.  Medium Effects on Charge Transfer in Metal Complexes. , 1998, Chemical reviews.

[26]  J. Yao,et al.  Five-stage near-infrared electrochromism in electropolymerized films composed of alternating cyclometalated bisruthenium and bis-triarylamine segments. , 2013, Inorganic chemistry.

[27]  J. Reynolds,et al.  The donor-acceptor approach allows a black-to-transmissive switching polymeric electrochrome. , 2008, Nature materials.

[28]  Jianwei Xu,et al.  Black-to-transmissive electrochromism of azulene-based donor–acceptor copolymers complemented by poly(4-styrene sulfonic acid)-doped poly(3,4-ethylenedioxythiophene) , 2013 .

[29]  Page E. Sebring,et al.  Synthesis and Catalytic Activity of Transition Metal Polymers Containing Alkane‐Linked Bipyridine and Terpyridine Ligands , 1995 .

[30]  M. Higuchi.  Stimuli-responsive metallo-supramolecular polymer films: design, synthesis and device fabrication , 2014 .

[31]  Louise A. Berben,et al.  Redox rich dicobalt macrocycles as templates for multi-electron transformations. , 2009, Chemical communications.

[32]  H. Nishihara,et al.  Construction of redox- and photo-functional molecular systems on electrode surface for application to molecular devices , 2007 .