Modulation of Intersystem Crossing Rate by Minor Ligand Modifications in Cyclometalated Platinum(II) Complexes / Shafikov Marsel Z.,Kozhevnikov Dmitry N.,Bodensteiner Michael,Brandl Fabian,Czerwieniec Rafal // INORGANIC CHEMISTRY. - 2016. - V. 55, l. 15. - P. 7457-7466.

ISSN/EISSN:

0020-1669 / 1520-510X

Type:

Article

Abstract:

Photophysical properties of four new platinum(II) complexes comprising extended ppy (Hppy = 2-phenylpyridine) and thpy (Hthpy = 2-(2'-thienyl)pyridine) cyclometalated ligands and acetylacetonate (acac) are reported. Substitution of the benzene ring of Pt-ppy complexes 1 and 2 with a more electron-rich thiophene of Pt-thpy complexes 3 and 4 leads to narrowing of the HOMO-LUMO gap and thus to a red shift of the lowest energy absorption band and phosphorescence band, as expected for low-energy excited states of the intraligand/metal-to-ligand charge transfer character. However, in addition to these conventional spectral shifts, another, at first unexpected, substitution effect occurs. Pt-thpy complexes 3 and 4 are dual emissive showing fluorescence about 6000 cm(-1) (similar to 0.7S eV) higher in energy relative to the phosphorescence band, while for Pt-ppy complexes 1 and 2 only phosphorescence is observed. For dual-emissive complexes 3 and 4, ISC rates k(ISC) are estimated to be in order of 10(9)-10(10) s(-1)) while k(ISC) of Pt-ppy complexes 1 and 2 is much faster amounting to 10(12) s(-1) or more. The relative intensities of the fluorescence and phosphorescence signals' of Pt-thpy complexes 3 and 4 depend on the excitation wavelength; Showing that hyper-intersystem crossing (HISC) in the complexes is observably significant.

Author keywords:

AGGREGATION-INDUCED EMISSION; LIGHT-EMITTING DEVICES; TRANSITION-METAL-COMPLEXES; DISCRETE ORGANOPLATINUM(II) METALLACYCLES; ORGANIC ELECTROLUMINESCENT DEVICES; IRIDIUM(III) COMPLEXES; EXCITED-STATES; DUAL EMISSION; HEAVY-ATOM; DIPLATINUM(II,II) COMPLEXES

DOI:

10.1021/acs.inorgchem.6b00704

Web of Science ID:

ISI:000380864900037

Соавторы в МНС:

Другие поля

Поле	Значение
Month	AUG 1
Publisher	AMER CHEMICAL SOC
Address	1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Language	English
EISSN	1520-510X
Keywords-Plus	AGGREGATION-INDUCED EMISSION; LIGHT-EMITTING DEVICES; TRANSITION-METAL-COMPLEXES; DISCRETE ORGANOPLATINUM(II) METALLACYCLES; ORGANIC ELECTROLUMINESCENT DEVICES; IRIDIUM(III) COMPLEXES; EXCITED-STATES; DUAL EMISSION; HEAVY-ATOM; DIPLATINUM(II,II) COMPLEXES
Research-Areas	Chemistry
Web-of-Science-Categories	Chemistry, Inorganic \& Nuclear
Author-Email	shafikoff@gmail.com dnk.eburg@gmail.com rafal.czerwieniec@ur.de
ResearcherID-Numbers	Bodensteiner, Michael/H-5479-2011
ORCID-Numbers	Shafikov, Marsel/0000-0003-0495-0364 Czerwieniec, Rafal/0000-0003-4789-6273
Funding-Acknowledgement	Russian Foundation for Basic Research {[}12-03-31318]
Funding-Text	M.Z.S. is grateful to the Russian Foundation for Basic Research for financial support, project No. 12-03-31318. M.Z.S. also gratefully acknowledges Professor Burkhard Konig and Professor Hartmut Yersin (Regensburg) for kind help and hospitality.
Number-of-Cited-References	117
Usage-Count-Last-180-days	9
Usage-Count-Since-2013	32
Journal-ISO	Inorg. Chem.
Doc-Delivery-Number	DS6AU