Journal of Physical Chemistry & Biophysics
Open Access
ISSN: 2161-0398
ISSN: 2161-0398
Rabindranath Lo, Dana Nachtigallova, Andrej Antalik, Robert Sedlak, Debashree Manna, Jiri Tucek, Juri Ugolotti, Libor Veis, Ors Legeza,Jiri Pittner Radek Zboril and Pavel Hobza
Institute of Organic Chemistry and Biochemistry – CAS, Czech Republic
RCPTM - Palacky University, Czech Republic
J. Heyrovsky Institute of Physical Chemistry – CAS, Czech Republic
Charles University, Czech Republic
Wigner Research Centre for Physics, Hungary
Posters & Accepted Abstracts: J Phys Chem Biophys
Statement of the Problem: Iron(II) phthalocyanine (FePc), an important member of the phthalocyanines family has potential applications in the various fields, such as electrocatalysis, magnetic switching, electrochemical sensing, and phototheranostics. Inspite of the importance of electronic properties of FePc in such wide applications, a reliable determination of its ground-state is still challenging. Here we present combined state of the art computational methods and experimental approaches i. e. M�?¶ssbauer spectroscopy and SQUID magnetic measurements to identify the ground-state of FePc. Methodology & Theoretical Orientation: The structures of FePc in different spin states have been obtained with various DFT functionals (B97-D3, BHLYP and B2-PLYP-D3). Multi-reference calculations have been performed using DFT optimized geometries. �?²-Iron(II)phthalocyanine (�?²-FePc) has been obtained from a commercial source. Chlorobenzene have been used for the 57Fe M�?¶ssbauer spectroscopy measurements in the frozen state. Findings: Depending on the functional, DFT calculations assign either quintet or, more frequently triplet, ground-state. At the CASSCF level the quintet is by 22.2 kcal/mol more stable with respect to triplet, which is reduced to 8.6 kcal/mol in subsequent perturbation treatment. The same ordering was also found using the DMRG approach. The hyperfine parameters of M�?¶ssbauer spectra confirm the quintet for isolated FePc frozen in the low-polarity solvent. Conclusion & Significance: Multi-reference calculations clearly proved that the ground-state of the isolated FePc is quintet showing its larger stability with respect to the triplet ground-state previously favorized by DFT calculations. These conclusions perfectly correlate with experimental results based on M�?¶ssbauer spectroscopy and magnetic measurements of FePc frozen in chlorobenzene. In these conditions Fe(II)Pc behaves like in the gas-phase as verified by magnetic data. Recent Publications: 1. Trashin S et al. (2017) Singlet oxygen-based electrosensing by molecular photosensitizers Nat. Commun. 8:16108. 2. Filoti G, Kuzâ�?�?min M D, Bartolom�?© J (2006) M�?¶ssbauer study of the hyperfine interactions and spin dynamics in �?±-iron(II) phthalocyanine. Phys. Rev. B 74: 134420. 3. Kirner J F, Dow W, Scheidt W R (1976) Molecular stereochemistry of two intermediate-spin complexes. Iron(II) phthalocyanine and manganese(II) phthalocyanine. Inorg. Chem. 15(7):1685. 4. Berryman V E J, Boyd R J, Johnson E R (2015) Balancing exchange mixing in density-functional approximations for iron porphyrin. J. Chem. Theory Comput. 11(7):3022-3028.
Rabindranath Lo obtained his PhD in theoretical and computational chemistry from Central Salt & Marine Chemicals Research Instititute (CSIR) India. His is currently working as a Postdoctoral Fellow with Professor Pavel Hobza at the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic. His main research work focuses on theoretical and computational description of noncovalent interactions and their role in chemistry, bio disciplines and nanosciences. During his PhD studies, he worked on the strength and directionality of various halogen bonding, superbasicity and reactivation of acetylcholinesterase enzyme. Currently, he is working on the importance of non-covalent interactions to tune the electronic and magnetic properties of metal phthalocyanine complexes.
E-mail: rabindranath.lo@uochb.cas.cz