Department of Chemical and Biological Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK.
J Phys Chem B. 2010 Sep 16;114(36):11697-702. doi: 10.1021/jp102755h.
Seven different porphyrin compounds have been investigated as colorimetric gas sensors for a wide range of volatile organic compounds. The porphyrins examined were the free base and Mg, Sn, Zn, Au, Co, and Mn derivatives of 5,10,15,20-tetrakis[3,4-bis(2-ethylhexyloxy)phenyl]-21H,23H-porphine. Chloroform solutions of these materials were prepared and changes in their absorption spectra induced by exposure to various organic compounds measured. The porphyrins that showed strong responses in solution were selected, and Langmuir-Blodgett films were prepared and exposed to the corresponding analytes. This was done to determine whether they are useful materials for solid state thin film colorimetric vapor sensors. Porphyrins that readily coordinate extra ligands are shown to be suitable materials for colorimetric volatile organic compound detectors. However, porphyrins that already have bound axial ligands when synthesized only show a sensor response to those analytes that can substitute these axial ligands. The Co porphyrin displays a considerably larger response than the other porphyrins investigated which is attributed to a switch between Co(II) and Co(III) resulting in a large spectral change.
七种不同的卟啉化合物被研究作为宽范围挥发性有机化合物的比色气体传感器。所检查的卟啉是 5,10,15,20-四[3,4-双(2-乙基己氧基)苯基]-21H,23H-卟啉的自由碱基和 Mg、Sn、Zn、Au、Co 和 Mn 衍生物。这些材料的氯仿溶液被制备，并且暴露于各种有机化合物引起的它们的吸收光谱的变化被测量。在溶液中显示强响应的卟啉被选择，并且 Langmuir-Blodgett 膜被制备并且暴露于相应的分析物。这是为了确定它们是否是用于固态薄膜比色蒸气传感器的有用材料。显示出容易配位额外配体的卟啉是适用于比色挥发性有机化合物检测器的材料。然而，当合成时已经具有结合的轴向配体的卟啉仅对那些可以取代这些轴向配体的分析物显示传感器响应。Co 卟啉显示出比所研究的其它卟啉大得多的响应，这归因于 Co(II)和 Co(III)之间的转换，导致光谱的大变化。
