D-THIN FILMS OF FERROCENE DERIVATIVES - OPTICAL GAS-SENSING AND STRUCTURAL STUDIES

Langmuir-Blodgett and vacuum-deposited films of two ferrocene derivati ves were employed for sensing NO2 by the interference enhanced reflect ometry technique. A dialkylated derivative, 1,1'-dioctadecyl ferrocene , was two orders of magnitude more sensitive than the diacylated analo gue, but gave a less reversible response, The diacyl derivative 1,1'-d ioctadecanoyl ferrocene, was less sensitive, but gave a more reversibl e response; and when employed in a practical device based on an LED-ph otodiode configuration was able to detect NO2 at the 1 ppm level. Neit her material responded to CO in the conditions employed. Data from ato mic force microscopy (AFM) and Xray photoelectron spectroscopy (XPS) s uggested that higher concentrations (1%) of NO2 caused permanent chang e. (C) 1998 Elsevier Science S.A. All rights reserved.