TY - JOUR

T1 - Chromophore-Functionalized Phenanthro-diimine Ligands and Their Re(I) Complexes

AU - Кисель, Кристина Станиславовна

AU - Eskelinen, Toni

AU - Zafar, Waqar

AU - Соломатина, Анастасия Игоревна

AU - Hirva, Pipsa

AU - Грачева, Елена Валерьевна

AU - Туник, Сергей Павлович

AU - Кошевой, Игорь Олегович

N1 - Funding Information: The authors greatly appreciate financial support from the Russian Science Foundation (grant 16-43-03003, synthesis and photophysical studies) and the Finnish National Agency for Education for a CIMO Fellowship (K.S.K., structural characterization). We acknowledge grants of computer capacity from the Finnish Grid and Cloud Infrastructure (persistent identifier urn:nbn:fi:research-infras-2016072533). The work was carried out using the core facilities of St. Petersburg State University Research Park (Centre for Magnetic Resonance, Centre for Optical and Laser Materials Research, Centre for Chemical Analysis and Materials Research, and Centre for X-ray Diffraction Studies).

PY - 2018/6/4

Y1 - 2018/6/4

N2 - A series of diimine ligands has been designed on the basis of 2-pyridyl-1H-phenanthro[9,10-d]imidazole (L1, L2). Coupling the basic motif of L1 with anthracene-containing fragments affords the bichromophore compounds L3-L5, of which L4 and L5 adopt a donor-acceptor architecture. The latter allows intramolecular charge transfer with intense absorption bands in the visible spectrum (lowest λ abs 464 nm (ϵ = 1.2 × 10 4 M -1 cm -1) and 490 nm (ϵ = 5.2 × 10 4 M -1 cm -1) in CH 2Cl 2 for L4 and L5, respectively). L1-L5 show strong fluorescence in a fluid medium (φ em = 22-92%, λ em 370-602 nm in CH 2Cl 2); discernible emission solvatochromism is observed for L4 and L5. In addition, the presence of pyridyl (L1-L5) and dimethylaminophenyl (L5) groups enables reversible alteration of their optical properties by means of protonation. Ligands L1-L5 were used to synthesize the corresponding [Re(CO) 3X(diimine)] (X = Cl, 1-5; X = CN, 1-CN) complexes. 1 and 2 exhibit unusual dual emission of singlet and triplet parentage, which originate from independently populated 1ππ∗ and 3MLCT excited states. In contrast to the majority of the reported Re(I) carbonyl luminophores, complexes 3-5 display moderately intense ligand-based fluorescence from an anthracene-containing secondary chromophore and complete quenching of emission from the 3MLCT state presumably due to the triplet-triplet energy transfer ( 3MLCT → 3ILCT).

AB - A series of diimine ligands has been designed on the basis of 2-pyridyl-1H-phenanthro[9,10-d]imidazole (L1, L2). Coupling the basic motif of L1 with anthracene-containing fragments affords the bichromophore compounds L3-L5, of which L4 and L5 adopt a donor-acceptor architecture. The latter allows intramolecular charge transfer with intense absorption bands in the visible spectrum (lowest λ abs 464 nm (ϵ = 1.2 × 10 4 M -1 cm -1) and 490 nm (ϵ = 5.2 × 10 4 M -1 cm -1) in CH 2Cl 2 for L4 and L5, respectively). L1-L5 show strong fluorescence in a fluid medium (φ em = 22-92%, λ em 370-602 nm in CH 2Cl 2); discernible emission solvatochromism is observed for L4 and L5. In addition, the presence of pyridyl (L1-L5) and dimethylaminophenyl (L5) groups enables reversible alteration of their optical properties by means of protonation. Ligands L1-L5 were used to synthesize the corresponding [Re(CO) 3X(diimine)] (X = Cl, 1-5; X = CN, 1-CN) complexes. 1 and 2 exhibit unusual dual emission of singlet and triplet parentage, which originate from independently populated 1ππ∗ and 3MLCT excited states. In contrast to the majority of the reported Re(I) carbonyl luminophores, complexes 3-5 display moderately intense ligand-based fluorescence from an anthracene-containing secondary chromophore and complete quenching of emission from the 3MLCT state presumably due to the triplet-triplet energy transfer ( 3MLCT → 3ILCT).

KW - ANNIHILATION UP-CONVERSION

KW - CARBONYL-BIPYRIDINE COMPLEXES

KW - CHARGE-TRANSFER

KW - DPPZ COMPLEXES

KW - DUAL EMISSION

KW - IRIDIUM(III) COMPLEXES

KW - PHOTOPHYSICAL PROPERTIES

KW - RHENIUM(I) TRICARBONYL COMPLEXES

KW - TRANSFER EXCITED-STATES

KW - TRANSITION-METAL-COMPLEXES

UR - http://www.scopus.com/inward/record.url?scp=85048270973&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/chromophorefunctionalized-phenanthrodiimine-ligands-rei-complexes

U2 - 10.1021/acs.inorgchem.8b00422

DO - 10.1021/acs.inorgchem.8b00422

M3 - Article

C2 - 29749736

VL - 57

SP - 6349

EP - 6361

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 11

ER -