TY - JOUR
T1 - Intriguing influence of −COOH-driven intermolecular aggregation and acid-base interactions with N,N-dimethylformamide on the second-order nonlinear-optical response of 5,15 push-pull diarylzinc(II) porphyrinates
AU - Orbelli Biroli, Alessio
AU - Tessore, Francesca
AU - Righetto, Stefania
AU - Forni, Alessandra
AU - Macchioni, Alceo
AU - Rocchigiani, Luca
AU - Pizzotti, Maddalena
AU - Di Carlo, Gabriele
PY - 2017/6/5
Y1 - 2017/6/5
N2 - A series of 5,15 push–pull meso-diarylzinc(II) porphyrinates, carrying one or two −COOH or −COOCH3 acceptor groups and a −OCH3 or a −N(CH3)2 donor group, show in N,N-dimethylformamide and CHCl3 solutions a negative and solvent-dependent second-order nonlinear-optical (NLO) response measured by the electric-field-induced second-harmonic generation (EFISH) technique, different from the structurally related zinc(II) porphyrinate carrying a −N(CH3)2 donor group and a −NO2 acceptor group, where a still solvent-dependent but positive EFISH second-order response was previously reported. Moreover, when a −N(CH3)2 donor group and a −COOH acceptor group are part of a sterically hindered 2,12 push–pull β-pyrrolic-substituted tetraarylzinc(II) porphyrinate, the EFISH response is positive and solvent-independent. In order to rationalize these rather intriguing series of observations, EFISH measurements have been integrated by electronic absorption and IR spectroscopic investigations and by density functional theory (DFT) and coupled-perturbed DFT theoretical and 1H pulsed-gradient spin-echo NMR investigations, which prompt that the significant concentration effects and the strong influence of the solvent nature on the NLO response are originated by a complex whole of different aggregation processes induced by the −COOH group.
AB - A series of 5,15 push–pull meso-diarylzinc(II) porphyrinates, carrying one or two −COOH or −COOCH3 acceptor groups and a −OCH3 or a −N(CH3)2 donor group, show in N,N-dimethylformamide and CHCl3 solutions a negative and solvent-dependent second-order nonlinear-optical (NLO) response measured by the electric-field-induced second-harmonic generation (EFISH) technique, different from the structurally related zinc(II) porphyrinate carrying a −N(CH3)2 donor group and a −NO2 acceptor group, where a still solvent-dependent but positive EFISH second-order response was previously reported. Moreover, when a −N(CH3)2 donor group and a −COOH acceptor group are part of a sterically hindered 2,12 push–pull β-pyrrolic-substituted tetraarylzinc(II) porphyrinate, the EFISH response is positive and solvent-independent. In order to rationalize these rather intriguing series of observations, EFISH measurements have been integrated by electronic absorption and IR spectroscopic investigations and by density functional theory (DFT) and coupled-perturbed DFT theoretical and 1H pulsed-gradient spin-echo NMR investigations, which prompt that the significant concentration effects and the strong influence of the solvent nature on the NLO response are originated by a complex whole of different aggregation processes induced by the −COOH group.
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85020310937&partnerID=MN8TOARS
U2 - 10.1021/acs.inorgchem.7b00510
DO - 10.1021/acs.inorgchem.7b00510
M3 - Article
VL - 56
SP - 6438
EP - 6450
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 11
ER -