@article { ISI:000225548700006,
	title = {Spectroscopic study of phosphine-substituted oligothiophenes},
	journal = {JOURNAL OF PHYSICAL CHEMISTRY B},
	volume = {108},
	number = {49},
	year = {2004},
	month = {DEC 9},
	pages = {18815-18819},
	abstract = {The spectroscopic behaviour (solution and solid-state absorption and emission) of a series of mono(diphenylphosphino) and bis-(diphenylphosphino) alpha-substituted oligothiophenes varying in length from one to three thienyl rings is described. The absorption spectra red-shift with increasing oligomer length, and the spectra of the bisphosphines are red-shifted, relative to the monophosphines that contain the same number of thienyl groups. In solution, emission from the mono- and bithienyl compounds is broad and shows a large Stokes shift, attributed to a planar excited state due to the n {\textendash}> pi{*} nature of the excitation. Emission from the terthienyl compounds shows a much smaller Stokes shift and is attributed to a thienyl-based pi {\textendash}> pi{*} transition. In the solid state, similar effects are observed in both absorption and emission spectra. Density functional theory (DFT) calculations show that the contribution of the P lone pair to the highest occupied molecular orbital (HOMO) diminishes as the oligomer length increases, supporting the experimental results.},
	issn = {1520-6106},
	doi = {10.1021/jp047037g},
	author = {Stott, TL and Wolf, MO}
}
