title: The synthesis and photophysical studies of cyclometalated Pt(II) complexes with C,N,N-ligands containing imidazolyl donors.
abstract: Two new C,N,N-type ligands (HL(2) and HL(3)), containing a C(phenyl), a N(pyridyl), and a N(imidazolyl) donor, and their cycloplatinated complexes, [Pt(L(2))Cl] (1), [Pt(L(3))Cl] (2), [Pt(L(2))(PPh(3))](+) (3) and [Pt(L(3))(PPh(3))](+) (4), have been successfully synthesized and characterized. Spectroscopic and (3)MLCT luminescent properties of these Pt(II) cyclometalated complexes were found to be pH dependent. This was attributed to the protonation/deprotonation of the acidic 1-imidazolyl-NH moieties on the ligands. All the cycloplatinated complexes (both protonated and deprotonated forms) possessed two-photon excitability with two-photon absorption cross-sections ranging from 6.0 to 30.0 GM (protonated forms) and from 16.2 to 24.9 GM (deprotonated forms).
authors.affiliation: Department of Biology & Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR, China.
authors.forename: Yu-Man
authors.initials: YM
authors.lastname: Ho
authors.forename: Chi-Kin
authors.initials: CK
authors.lastname: Koo
authors.forename: Ka-Leung
authors.initials: KL
authors.lastname: Wong
authors.forename: Hoi-Kuan
authors.initials: HK
authors.lastname: Kong
authors.forename: Chris Tsz-Leung
authors.initials: CT
authors.lastname: Chan
authors.forename: Wai-Ming
authors.initials: WM
authors.lastname: Kwok
authors.forename: Cheuk-Fai
authors.initials: CF
authors.lastname: Chow
authors.forename: Michael Hon-Wah
authors.initials: MH
authors.lastname: Lam
authors.forename: Wai-Yeung
authors.initials: WY
authors.lastname: Wong