Xin Li

Research topics:

• Metal-assisted nonlinear optics
  We introduce a quantum mechanics capacitance molecular mechanics (QMCMM) approach for computation of linear and quadratic response properties of molecules in heterogeneous environments, such as metal surfaces or nanoparticles embedded in solvents. This approach enables studies of properties and spectra of systems embedded in or placed at arbitrary shaped metallic surfaces, clusters, or nanoparticles.
  
  
  
  Published papers:
  J. Chem. Theory Comput.: Two-Photon Absorption
  Phys. Chem. Chem. Phys.: Nonlinear Optical Properties
  J. Phys. Chem. C: Electronic Circular Dichroism
  J. Chem. Theory Comput.: Linear Response Properties
   
• Chemical Self-assemblies 
  Theoretical simulations provide insight into the working mechanisms of multifunctional self-assemblies based on unimolecular platforms and enables in silico design of promising nanomaterials for biological applications, as exemplified by our collaborated efforts on the realization of multicolor luminescence on unimolecular platforms and chirality control of gold nanoparticle superstructures. 
   
  
  
  Published papers:
  Phys. Chem. Chem. Phys.: Chiral Symmetry Breaking
  J. Am. Chem. Soc.: Topochemical Polymerization
  J. Am. Chem. Soc.: Templated Chirality Control
  J. Am. Chem. Soc.: Unimolecular Multicolor Luminescence
   
• Dye-sensitized solar cells 
  In collaboration with experimental chemists, time-dependent density functional theory calculations help figure out the potential of the novel D-A-π-A framework proposed for designing sensitizers for dye-sensitized solar cells. The ancillary acceptor narrows the bandgap and broadens the absorption spectrum by providing strong electron-withdrawing character and enhancing electron delocalization, which eventually lead to improved light-harvesting efficiency. 
   
  
  
  Published papers:
  ACS Appl. Mater. Interfaces: Pyrido[3,4-b]pyrazine
  J. Mater. Chem. C: Bis(octyloxy)benzo-[c][1,2,5]thiadiazole
  ACS Sustain. Chem. Eng.: Benzothiadiazole in D-A-π-A
  Adv. Funct. Mater.: D-A-π-A Sensitizer
   
• Luminescent sensors 
  In collaboration with experimentalists, we developed fluorescence "turn-on" cyanide probes which has the advantages of simplicity, high sensitivity, low cost, and extraordinary signal-to-noise ratio, to cope with the environmental contamination problems of cyanide due to its high toxicity and widespread use in industrial processes. In particular, electronic structure calculations helped to elucidate the underlying mechanism of fluorescence-based sensing. 
  
  
  
  Published papers:
  RSC Adv.: Detection of Cyanide in Aqueous Media
  Sens. Actuators B Chem.: Red "Turn-on" Cyanine Chemodosimeter
  Chem. Commun.: Fluorescence "Turn-on" Cyanide Probes
  ACS Appl. Mater. Interface: Near-Infrared Cyanide Chemodosimeter