TY - JOUR

T1 - Quantum Interference in Mixed‐Valence Complexes

T2 - Tuning Electronic Coupling Through Substituent Effects

AU - Harrison, Daniel P.

AU - Grotjahn, Robin

AU - Naher, Masnun

AU - Ghazvini, Seyed M. B. H.

AU - Mazzucato, Daniel M.

AU - Korb, Marcus

AU - Moggach, Stephen A.

AU - Lambert, Colin

AU - Kaupp, Martin

AU - Low, Paul J.

PY - 2022/11/7

Y1 - 2022/11/7

N2 - Whilst 2- or 5-OMe groups on the bridging phenylene ring in [{Cp*(dppe)RuCΞC} 2 (μ-1,3-C 6 H 4 )] + have little influence on the electronic structure of this weakly coupled mixed valence complex, a 4-OMe substituent enhances ground state electron delocalization, and increases the intensity of the IVCT transition. Vibrational frequency and TDDFT calculations (LH20t-D3(BJ), def2-SVP, COSMO (CH 2 Cl 2 )) on ([{Cp*(dppe)RuCΞC} 2 (μ-1,3-C ­6 ­H 3 -n-OMe)] + (n = 2, 4, 5) models are in excellent agreement with the experimental results. The stronger ground state coupling is attributed to the change in composition of the b-HOSO brought about by the 4-OMe group, which is ortho or para to each of the metal fragments. The intensity of the IVCT transition increases with the greater overlap of the β-HOSO and β-LUSO, whilst the relative phases of the β-HOSO and β-LUSO in the 4-OMe substituted complex are consistent with predictions of constructive quantum interference from molecular circuit rules.

AB - Whilst 2- or 5-OMe groups on the bridging phenylene ring in [{Cp*(dppe)RuCΞC} 2 (μ-1,3-C 6 H 4 )] + have little influence on the electronic structure of this weakly coupled mixed valence complex, a 4-OMe substituent enhances ground state electron delocalization, and increases the intensity of the IVCT transition. Vibrational frequency and TDDFT calculations (LH20t-D3(BJ), def2-SVP, COSMO (CH 2 Cl 2 )) on ([{Cp*(dppe)RuCΞC} 2 (μ-1,3-C ­6 ­H 3 -n-OMe)] + (n = 2, 4, 5) models are in excellent agreement with the experimental results. The stronger ground state coupling is attributed to the change in composition of the b-HOSO brought about by the 4-OMe group, which is ortho or para to each of the metal fragments. The intensity of the IVCT transition increases with the greater overlap of the β-HOSO and β-LUSO, whilst the relative phases of the β-HOSO and β-LUSO in the 4-OMe substituted complex are consistent with predictions of constructive quantum interference from molecular circuit rules.

KW - General Chemistry

KW - Catalysis

U2 - 10.1002/anie.202211000

DO - 10.1002/anie.202211000

M3 - Journal article

C2 - 36031588

VL - 61

JO - Angewandte Chemie International Edition

JF - Angewandte Chemie International Edition

SN - 1433-7851

IS - 45

M1 - e202211000

ER -