Research Interests

Research in our group is focused on the design and synthesis of novel pi-conjugated macromolecules that has potential applications in chemistry, biology, and material science.  Examples of these applications include light-emitting, light-harvesting, and chemical-sensing.  

Luminescent Polymers

A major recent development in the field of molecular electronics has been the discovery of electroluminescent conjugated polymers. Emission of bright light when excited by flow of electricity through the conjugated polymers makes these materials attractive for commercial applications such as backlights for liquid crystal displays, large screen displays, and lasers. A reliable polymeric light-emitting diode device requires the polymer emissive layer to exhibit high efficiencies in photoluminescence and electroluminescence. Our goal is to develop such materials to meet the practical requirements, through design and synthesis of new polymers with high luminescence and improved stability. The applications include light-emitting diodes and photovoltaic devices. 

Carbon Nanotubes

Solubilizing and purifying carbon nanotubes remains one of the foremost technological barriers in realization of their potential applications.  In this direction, we are interested in using soluble polymers to effectively disperse single-walled carbon nanotubes (SWNTs) into solutions.   The specific conformation associated with each polymer structure could play important roles in selective interaction with different types of SWNTs.  For example, poly[(m-phenylenevinylene)-alt-(p-phenylenevinylene)] forms a cavity of about 1.3 nm, which preferably wraps up the SWNT of comparable diameters (1.0-1.2 nm).  The vinylene bond geometry is also found to influence the metallic tube selectivity.

Chemical Sensors

The luminescence signals of a probe molecule change, sometimes drastically, with the chemical environment.  In this direction, we are interested in developing sensor materials that can specifically target the species of biological importance, such as zinc (II) cation, proteins and DNA. By using analyte-binding to trigger the excited state intramolecular proton transfer (ESIPT), our recent progress has led to specific recognition of pyrophosphate and various cations, which has the potential to influence the DNA sequencing.      

Selected Publications 

  1. Yongqian Xu, Mingming Guo, Xiaopeng Li, Chrys Wesdemiotis and Yi Pang, “Formation of linear supramolecular polymers that is based on host-guest assembly in water.”  Chem. Commun., 2011, 47(31), 8883-8885.
  2. Tongyan Zhang, Shiguo Sun, Fengyu Liu, Yi Pang, Jiangli Fan and Xiaojun Peng, “Interaction of DNA and a series of aromatic donor–viologen acceptor molecules with and without the presence of CB[8].” Phys. Chem. Chem. Phys., 2011, 13(20), 9789-9795.
  3. Yongqian Xu, Andrey Malkovskiy, Yi Pang, “A Graphene Binding-Promoted Fluorescence Enhancement for BSA Recognition.” Chem. Commun, 2011, 47(23), 6662-6664.
  4. Weihua Chen, Yu Xing, Yi Pang, “A Highly Selective Pyrophosphate Sensor Based on ESIPT Turn-On in Water”, Org. Lett., 2011, 13(6), 1362-1365.
  5. Yongqian Xu, Andrey Malkovskiy, Qiuming Wang and Yi Pang “Molecular Assembly of A Squaraine Dye with Cationic Surfactant and nucleotides: Its Impact on Aggregation and Fluorescence Response.” Org. & Biomol. Chem., 2011, 9 (8), 2878-2884.  
  6. Yongqian Xu, Yi Pang “Zn2+-Trigged Excited-State Intramolecular Proton Transfer: A Sensitive Probe with Near-infrared Emission from Bis(benzoxazole) Derivative.” Dalton Transaction, 2011, 40 (7), 1503-1509.
  7. Jiping Ma, Zhongtian Du, Jie Xu, Qinghui Chu, Yi Pang, “Efficient Aerobic Oxidation of 5-Hydroxymethylfurfural to 2,5-Diformylfuran, and Synthesis of a Fluorescent Material”, ChemSusChem2011, 4, 51-54.
  8. Junhong Yao, Yusheng Chen, Yi Pang “Application of Sonochemistry in the Isomerization of Carbon-Carbon double bond.”  J. Polym. Sci. Part A: Polym. Chem., 2010, 48, 5254-5257.
  9. Yongqian Xu, Zhiyong Li, Andrey Malkovskiy, Shiguo Sun and Yi Pang, “Aggregation control of squaraines and their use as near infrared fluorescent sensor for protein.” J. Phys. Chem. B.  2010, 114 (25), 8574–8580. 
  10. Shiguo Sun, Yanxia He, Zhigang Yang, Yi Pang, Fengyu Liu, Jiangli Fan, Licheng Sun and Xiaojun Peng, “Synthesis and DNA photocleavage study of Ru(bpy)32+-(CH2)n-MV2+ complexes.”  Dalton Transactions, 2010, 39, 4411-4416.
  11. Yongqian Xu, Matthew Panzer, Xiaopeng Li, Wiley Youngs, Yi Pang, “Host-Guest Assembly of Squaraine Dye in Cucurbit[8]uril: Its Implication in Fluorescent Probe for Mercury Ions” Chem. Commun., 2010, 46, 4073-4075.
  12. Yongqian Xu and Yi Pang, “Zinc Binding-Induced Near-Infrared Emission from Excited-State Intramolecular Proton Transfer of a Bis(benzoxazole) Derivative”  Chem. Commun, 2010, 46, 4070-4072. 
  13. Qinghui Chu, Doug A. Medvetz, Matt Panzner, and Yi Pang  “A Fluorescent Bis(benzoxazole) Ligand: Toward Binuclear Zn(II)-Zn(II) Assembly.”  Dalton Transactions, 2010, 39(22), 5254-5259.
  14. Weihua Chen, Yi Pang, “Excited-State Intramolecular Proton Transfer in 2-(2’,6’-Dihydroxyphenyl)benzoxazole: Effect of Dual Hydrogen Bonding on the Optical Properties”  Tetrahedron Letter 2010, 51, 1914-1918. 
  15. Wenhui Yi, Andrey Malkovskiy, Yongqian Xu, Xiao-Qian Wang,Alexei P. Sokolov, Marisabel Lebron Colon, Michael Meador, Yi Pang “Polymer Conformation-Assisted Wrapping of Single-Walled Carbon Nanotube:  The Impact of cis-Vinylene Linkage” Polymer, 2010, 51, 475-481.
  16. Victor Banjoko, Yongqian Xu, Eric Mintz, Yi Pang, “Terpyridine-Functionalized PPVs: The Role of meta-Phenylene Linkage on the Cu2+ and Zn2+ Chemisensor”, Polymer.  2009, 50, 2001-2009.
  17. Jianfang Chai, Chao Wang, Li Jia, Yi Pang, Matthew Graham, and Stephen Z. D. ChengSynthesis and Electrochemical Properties of a New Class of Boron-Containing n-Type Conjugated Polymers.”  Synthetic Metals, 2009, 159 (14), 1443-1449.
  18. Weihua Chen and Yi Pang, “Efficient Synthesis of 2-(2’-Hydroxyphenyl)benzoxazole by Palladium(II)-Catalyzed Oxidative Cyclization Tetrahedron Letter, 2009, 50, 6680–6683.
  19. Tongyan Zhang, Shiguo Sun, Yi Pang, Xiaojun Peng, Jiangli Fan, Fengyu Liu “Redox-Induced Partner Radical Formation and Its Dynamic Balance with Radical Dimer in  Cucurbit[8]uril.”  Phys. Chem. Chem. Phys., 2009, 11 (47), 11134-11139. 
  20. Shiguo Sun, Yang Yang, Fengyu Liu, Yi Pang, Jiangli Fan, Lichen Sun, Xiaojun Peng “ A Study of Highly Efficient Bimetallic Ruthenium tris-Bipyridyl ECL Labels for Coreactant System”  Anal. Chem.  2009, 81, 10227-10231.