title: Förster Energy Transport in Metal-Organic Frameworks Is Beyond Step-by-Step Hopping.
abstract: Metal-organic frameworks (MOFs) with light-harvesting building blocks designed to mimic photosynthetic chromophore arrays in green plants provide an excellent platform to study exciton transport in networks with well-defined structures. A step-by-step exciton random hopping model made of the elementary steps of energy transfer between only the nearest neighbors is usually used to describe the transport dynamics. Although such a nearest neighbor approximation is valid in describing the energy transfer of triplet states via the Dexter mechanism, we found it inadequate in evaluating singlet exciton migration that occurs through the Förster mechanism, which involves one-step jumping over longer distance. We measured migration rates of singlet excitons on two MOFs constructed from truxene-derived ligands and zinc nodes, by monitoring energy transfer from the MOF skeleton to a coumarin probe in the MOF cavity. The diffusivities of the excitons on the frameworks were determined to be 1.8 × 10(-2) cm(2)/s and 2.3 × 10(-2) cm(2)/s, corresponding to migration distances of 43 and 48 nm within their lifetimes, respectively. "Through space" energy-jumping beyond nearest neighbor accounts for up to 67% of the energy transfer rates. This finding presents a new perspective in the design and understanding of highly efficient energy transport networks for singlet excited states.
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, PR China.
authors.forename: Qiongqiong
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, PR China.
authors.forename: Cankun
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, PR China.
authors.forename: Lingyun
authors.initials: L
authors.lastname: Cao
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, PR China.
authors.forename: Zi
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, PR China.
authors.forename: Bing
authors.initials: B
authors.lastname: An
authors.affiliation: Department of Chemistry, University of Chicago , 929 E 57th Street, Chicago, Illinois 60637, United States.
authors.forename: Zekai
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, PR China.
authors.forename: Ruiyun
authors.initials: R
authors.lastname: Huang
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, PR China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, PR China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.affiliation: Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, PR China.|Department of Chemistry, University of Chicago , 929 E 57th Street, Chicago, Illinois 60637, United States.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Lin