The effects of extended π-conjugation in bipyridyl ligands on the tunable photophysics, triplet excited state and optical limiting properties of Pt(ii) naphthalimidyl acetylide complexes. Issue 40 (27th September 2019)

• Record Type: Journal Article
• Authors: Zhu, Senqiang; Liu, Hao; Wang, Kunyan; Cheng, Qian; Ma, Zhenxing; Liu, Rui; Song, Guangliang; Zhu, Hongjun
• Is Part Of: Dalton transactions. Volume 48:Issue 40(2019)
• Page Start: 15105
• Page End: 15113
• Publication Date: 2019-09-27
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c9dt02595b
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Pt(ii ) complexes that exhibit long-lived triplet excited state lifetimes are promising for optical power limiting materials. Abstract : Pt(ii ) complexes that exhibit long-lived triplet excited state lifetimes are promising for optical power limiting materials. The introduction of large π-conjugated substituents can switch the triplet excited state to a long-lived 3 π, π* state. Herein, we report four Pt(ii ) diimine complexes with high π-conjugation via inserting an aryl group on the diimine ligand. Their photophysical properties were investigated using spectroscopic techniques. All the complexes exhibit strong ground absorption bands in their UV-Vis absorption spectra (maximum peaks ranging from 370 to 530 nm) and long-lived emission and triplet excited states. The insertion of π-conjugated substituents induces a pronounced red-shift in the ground state absorption and longer emission lifetime. Broadband transient absorption spectra in the visible-NIR region and Z -scan properties under 532 nm were carried out on the Pt(ii ) diimine complexes, resulting in a remarkably strong reverse saturable absorption at 532 nm for nanosecond laser pulses. Otherwise, the high π-conjugation in the bipyridyl ligand increases the reverse saturable absorption. Therefore, these Pt(ii ) diimine complexes with high π-conjugation are excellent candidates for devices that require strong reverse saturable absorption.