Organic Crystals Made to Order

1. Organic Crystals Made to Order Sol M. Gruner, Cornell University, DMR 0936384 Intellectual Merit: Organic materials hold tremendous promise for inexpensive electronic and optoelectronic devices such as solar cells, but these applications require the challenging step of coaxing molecules into crystalline form. Covalent organic frameworks (COFs) are a general approach to overcoming this challenge, in which molecules are specifically designed to form predictable crystalline structures. In the April 8th issue of Science, Cornell researchers report the first successes at growing oriented COF films that have high enough order for the molecules to retain their light-absorbing properties essential for technological applications. (left) COF crystalline “chain-link fence”. (right, top) GISAXS images showing stacked 2D order; (right, bottom) UV spectroscopy showing light absorption activity. John W. Colson, Arthur R. Woll, Arnab Mukherjee, Mark P. Levendorf, Eric L. Spitler, Virgil B. Shields, Michael G. Spencer, Jiwoong Park, William R. Dichtel, "Oriented 2D Covalent Organic Framework Thin Films on Single-Layer Graphene," Science 332, 228 (2011), DOI: 10.1126/science.1202747 CHESS DMR-0936384 2011_1