ChemInform Abstract: PHENOPHOSPHAZINES. V. 7,12‐DIHYDROBENZO(A)PHENOPHOSPHAZINES

Rozanel'skaya, N. A.; Bokanov, A. I.; Негребецкий, В. В.; Stepanov, B. I.

doi:10.1002/chin.198211273

Cited by 2 publications

(4 citation statements)

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“…The emission of both PTP and PT is weak and exhibits a large Stokes shift (see Figures and ). Triphenylphosphine also exhibits a large Stokes shift, with emission occurring between 450 nm and 500 nm, depending on the polarity of the solvent used (450 nm in diethyl ether and 475 nm in acetonitrile). , In triphenylphosphine, this emission is assigned as a π*→ n transition, as triphenylphosphine oxide emits at 290 nm with a small Stokes shift. A large Stokes shift typically indicates a change in geometry from the ground state to the excited state, and for triphenylphosphine, this is believed to be a fast geometrical conversion from a pyramidal ground state to a more-planar excited state .…”

Section: Resultsmentioning

confidence: 99%

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Spectroscopic Study of Phosphine-Substituted Oligothiophenes

Stott

Wolf

2004

J. Phys. Chem. B

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The spectroscopic behavior (solution and solid-state absorption and emission) of a series of mono-(diphenylphosphino) and bis-(diphenylphosphino) R-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 nfπ* nature of the excitation. Emission from the terthienyl compounds shows a much smaller Stokes shift and is attributed to a thienyl-based πfπ* 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. IntroductionConjugated oligomers and polymers are organic materials with many interesting properties, including electronic conductivity, luminescence, and color. 1 Pendant metal groups, which can be attached using several different coordinating groups, may be used to modify the electronic and optical properties of these materials. [2][3][4][5][6][7][8][9][10][11] Our group has investigated the use of phosphine substituents as ligating groups, 12-16 which is an approach driven both by the versatility of phosphines in binding a wide variety of metals 17 and the benefit of having only a single atom (P) between the metal and conjugated backbone, facilitating strong electronic interactions. It is therefore of interest to understand the electronic behavior of phosphine-substituted oligothiophenes prior to the coordination of a metal, because this is important to help build an understanding of the behavior of corresponding metal complexes.The electronic effects of a range of substituents both in the terminal (R) position and the internal ( ) position of thiophenes and oligothiophenes have been studied. 18 However, no systematic study of the influence of phosphine substituents on the electronic properties of the conjugated backbone exists. Diarylamino-substituted oligothiophenes, ranging from one to six rings in length, have been prepared. 19 These compounds show strong bathochromic shifts, relative to the parent oligomers in both absorption and emission spectra; in addition, because nitrogen and phosphorus are Group 15 congeners, it is interesting to compare these compounds to the phosphino analogues. Here, we report the absorption and emission spectra of the series of monosubstituted and disubstituted oligothiophenes shown in Chart 1, both in solution and in the solid state as thin films. The disubstituted thiophenes are of interest because of the possibility of binding metals to the ends of these ligands, which is relevant to "molecular wire" studies with these conjugated compound...

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Section: Resultsmentioning

confidence: 99%

“…1 H NMR (CDCl 3 ): δ 7.37-7.27 (m, 10H), 7.17 (dd, J ) 4.2, 2.3 Hz, 1H), 7.01 (ddd, J ) 4.8, 3.7, 1.2 Hz, 1H). 31 P{ 1 H} NMR (CDCl 3 ): δ 19 (s).…”

Section: 5-bis(diphenylphosphino)thiophene (Ptp)mentioning

confidence: 99%

Spectroscopic Study of Phosphine-Substituted Oligothiophenes

Stott

Wolf

2004

J. Phys. Chem. B

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“…McHattie obtained a number of amides of thiophenophosphazinic acid (34) by heating a benzene solution of the acid chloride 22a with ammonia or a primary or secondary amine. These amides are tabulated in Mann's book.8 Several other amides of 34 were later prepared by a similar procedure15 and are mentioned in section VI.…”

Section: Halogenationmentioning

confidence: 99%

“…It was concluded that the phosphorus atom was so remote from the reaction center in these cases that the differences in their electronic effects were not manifest. Thiophenophosphazinic acid (34) was first prepared by Haring,5 who noted that it was soluble in aqueous Na2C03 and that it could be reprecipitated with HC1.…”

Section: T H I S C O N T E N T Imentioning

confidence: 99%