NEW COMPLEXES OF FULLERENES C-60 AND C-70 WITH ORGANIC DONOR DBTTF - SYNTHESIS, SOME PROPERTIES AND CRYSTAL-STRUCTURE OF DBTTF-CENTER-DOT-C-60-CENTER-DOT-C6H6 (DBTTF=DIBENZOTETRATHIAFULVALENE)

New complexes of fullerenes C-60 and C-70 with dibenzotetrathiafulvale ne (DBTTF), DBTTF . C-60 . C6H6, DBTTF . C-60 . Py and DBTTF . C-70 . C6H6, were obtained. The crystal structure of DBTTF . C-60 . C6H6 was determined. The arrangement of fullerene molecules is approximately si mple cubic packing where each C-60 molecule is located in slightly dis torted octahedral surrounding. DBTTF molecules have a concave conforma tion. Xray photoelectron spectroscopy (XPS) and IR spectroscopy show o nly weak charge transfer in these compounds. A weak charge transfer ba nd near 900 nm was found in the UV-Vis-NIR absorption spectrum of DBTT F . C-60 . C6H6 single crystals. DBTTF molecules are coordinated on C- 60 ones by pi-pi and n-pi interactions. It was shown that the steric d iscrepancy between DBTTF and C-60 molecules does not provide favourabl e conditions for charge transfer in the DBTTF . C-60 . C6H6 complex. ( C) 1998 Elsevier Science S.A.