PMID- 36128935
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20221005
IS  - 1463-9084 (Electronic)
IS  - 1463-9076 (Linking)
VI  - 24
IP  - 38
DP  - 2022 Oct 5
TI  - Self-aggregation, H-bonding, and photoresponse in film and solution states of 
      azobenzene containing polyurea.
PG  - 23447-23459
LID - 10.1039/d2cp01200f [doi]
AB  - We critically understand the hydrogen bonding interactions and electronic 
      transitions occurring in a thin film as well as in solution of a photo-responsive 
      polymer, azo-polyurea (azo-PU). We synthesize azo-PU by covalent attachment of 
      the azobenzene chromophore to the main chain of polyurea. Azo-PU shows reversible 
      photoisomerization between trans and cis states upon light exposure, the 
      occurrence of which is typically analysed using the pi-pi* and n-pi* electronic 
      transition peaks in the UV-visible absorption spectrum. We find that the pi-pi* and 
      n-pi* bands undergo a redshift and blueshift respectively on dissolving azo-PU in 
      DMF solvent, resulting in a single overlapped peak in the spectrum. However, upon 
      UV irradiation, these bands split into two independent transitions that are 
      characteristic of azo-PU solid films. These observations are explained based on 
      the changes in polymer-polymer and polymer-solvent interactions through hydrogen 
      bonding and self-aggregation tendency. The experimental findings are corroborated 
      using DFT simulations which provide useful insights into electronic orbital 
      transitions, electron distribution, and hydrogen bonding interaction through IR 
      vibrational modes.
FAU - Erekath, Swathi
AU  - Erekath S
AD  - Department of Metallurgical and Materials Engineering, Indian Institute of 
      Technology Madras, Chennai-600036, India. sreeram@iitm.ac.in.
FAU - Chordiya, Kalyani
AU  - Chordiya K
AUID- ORCID: 0000-0003-4037-1984
AD  - ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3., Szeged, H-6728, 
      Hungary. mousumi.upadhyayKahaly@eli-alps.hu.
AD  - Institute of Physics, University of Szeged, Dom ter 9, H-6720 Szeged, Hungary.
FAU - Vidhya, K V
AU  - Vidhya KV
AD  - Department of Metallurgical and Materials Engineering, Indian Institute of 
      Technology Madras, Chennai-600036, India. sreeram@iitm.ac.in.
FAU - Kahaly, Mousumi Upadhyay
AU  - Kahaly MU
AUID- ORCID: 0000-0002-8128-8397
AD  - ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3., Szeged, H-6728, 
      Hungary. mousumi.upadhyayKahaly@eli-alps.hu.
AD  - Institute of Physics, University of Szeged, Dom ter 9, H-6720 Szeged, Hungary.
FAU - Kalpathy, Sreeram K
AU  - Kalpathy SK
AUID- ORCID: 0000-0002-0064-6413
AD  - Department of Metallurgical and Materials Engineering, Indian Institute of 
      Technology Madras, Chennai-600036, India. sreeram@iitm.ac.in.
LA  - eng
PT  - Journal Article
DEP - 20221005
PL  - England
TA  - Phys Chem Chem Phys
JT  - Physical chemistry chemical physics : PCCP
JID - 100888160
SB  - IM
EDAT- 2022/09/22 06:00
MHDA- 2022/09/22 06:01
CRDT- 2022/09/21 05:22
PHST- 2022/09/22 06:00 [pubmed]
PHST- 2022/09/22 06:01 [medline]
PHST- 2022/09/21 05:22 [entrez]
AID - 10.1039/d2cp01200f [doi]
PST - epublish
SO  - Phys Chem Chem Phys. 2022 Oct 5;24(38):23447-23459. doi: 10.1039/d2cp01200f.