Unknown

Dataset Information

0

Heteroleptic mer-[Cr(NNN)(CN)3] complexes: synthetic challenge, structural characterization and photophysical properties.


ABSTRACT: The substitution of three water molecules around trivalent chromium in CrBr3·6H2O with the tridentate 2,2':6',2''-terpyridine (tpy), N,N'-dimethyl-N,N'-di(pyridine-2-yl)pyridine-2,6-diamine (ddpd) or 2,6-di(quinolin-8-yl)pyridine (dqp) ligands gives the heteroleptic mer-[Cr(L)Br3] complexes. Stepwise treatments with Ag(CF3SO3) and KCN under microwave irradiations provide mer-[Cr(L)(CN)3] in moderate yields. According to their X-ray crystal structures, the associated six-coordinate meridional [CrN3C3] chromophores increasingly deviate from a pseudo-octahedral arrangement according to L = ddpd ≈ dpq ≪ tpy; a trend in line with the replacement of six-membered with five-membered chelate rings around CrIII. Room-temperature ligand-centered UV-excitation at 18 170 cm-1 (λexc = 350 nm), followed by energy transfer and intersystem crossing eventually yield microsecond metal-centered Cr(2E → 4A2) phosphorescence in the red to near infrared domain 13 150-12 650 cm-1 (760 ≤ λem ≤ 790 nm). Decreasing the temperature to liquid nitrogen (77 K) extends the emission lifetimes to reach the millisecond regime with a record of 4.02 ms for mer-[Cr(dqp)(CN)3] in frozen acetonitrile.

SUBMITTER: Chong J 

PROVIDER: S-EPMC8922558 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature

altmetric image

Publications

Heteroleptic <i>mer</i>-[Cr(N<sup>∩</sup>N<sup>∩</sup>N)(CN)<sub>3</sub>] complexes: synthetic challenge, structural characterization and photophysical properties.

Chong Julien J   Besnard Céline C   Cruz Carlos M CM   Piguet Claude C   Jiménez Juan-Ramón JR  

Dalton transactions (Cambridge, England : 2003) 20220315 11


The substitution of three water molecules around trivalent chromium in CrBr<sub>3</sub>·6H<sub>2</sub>O with the tridentate 2,2':6',2''-terpyridine (tpy), <i>N</i>,<i>N</i>'-dimethyl-<i>N</i>,<i>N</i>'-di(pyridine-2-yl)pyridine-2,6-diamine (ddpd) or 2,6-di(quinolin-8-yl)pyridine (dqp) ligands gives the heteroleptic <i>mer</i>-[Cr(L)Br<sub>3</sub>] complexes. Stepwise treatments with Ag(CF<sub>3</sub>SO<sub>3</sub>) and KCN under microwave irradiations provide <i>mer</i>-[Cr(L)(CN)<sub>3</sub>] i  ...[more]

Similar Datasets

| S-EPMC11496276 | biostudies-literature
| S-EPMC8252544 | biostudies-literature
| S-EPMC10254484 | biostudies-literature
| S-EPMC7497214 | biostudies-literature
| S-EPMC9268030 | biostudies-literature
| S-EPMC10885143 | biostudies-literature
| S-EPMC9175238 | biostudies-literature
| S-EPMC10421489 | biostudies-literature
| S-EPMC6895955 | biostudies-literature
| S-EPMC10176475 | biostudies-literature