Page 22 - CFM-Annual Newsletter 2021

• Enhancement of second-order non-linear optical properties of centrosymmetric Ferrocenyl
Borasiloxane by a broken-symmetry approach

The Journal of Physical Chemistry C 125, 8732 (2021)
T. Viswanathan, M. Gopalakrishnan, K. Thirumoorthy, M. Prakash, and N. Palanisami

A new eight-membered centrosymmetric Centrosymmetry Broken symmetry
ferrocenyl borasiloxane and its pyridine adduct

were synthesized and spectroscopically Symmetry
Breaking
characterized. The enhanced second-harmonic
generation efficiency (1.88 times) and ground-
state dipole moment of pyridine adduct was

achieved by breaking the symmetry by forming Weak SHG Enhanced SHG
four coordinated boron pyridine adducts in the solid state. Further, optical and NLO properties were

supported by DFT, which revealed enhanced hyperpolarizability (β0), and dipole moment (μtot) of
pyridine adduct.

• Novel Ferrocene-appended β-Ketoimines and related BF2 derivatives with significant

aggregation-induced emission and second-order non-linear optical properties
Chemistry-A European Journal 27, 7124 (2021)
E. David, A. Colombo, C. Dragonetti, and N. Palanisami

A series of new β-ketoimines containing a ferrocene moiety with BF2 derivatives were
synthesized and structurally characterized. β-ketoimines exhibit a weak emission,
attributable to the excited state intramolecular proton transfer (ESIPT) phenomenon.
This ESIPT effect is suppressed upon restriction of the keto-enamine tautomerism by
adding BF3·OEt2, which affords the related BF2 complexes, characterized by an
enhancement of the fluorescence through the ICT effect. Electric field-induced second
harmonic generation (EFISH) technique has been utilized to measure the second-
order non-linear optical (NLO) properties. The μβ1907 value of all β-ketoimines
increases upon the formation of the related BF2 complex, mainly due to an
enhancement of the ground state dipole moment. These novel compounds are
excellent multifunctional candidates for NLO and luminescence applications.

Fellowships

Student Name Fellowship Award Number

Mr. S. Prabu Senior research fellow (ICMR) 45/30/2020-BIO/BMS
Mr. T. Viswanathan Senior research fellow (CSIR) 09/844(0097)/2020-EMR-I

CFM Newsletter Jan. – Dec. 2021 22 Issue – 1