Abstract
The detailed temperature-dependent IR and Raman spectra were used to study and understand the mechanism of structural phase transition occurring at 175K in manganese hypophosphite templated with formamidinium (FA+) ions, [FA]Mn(H2POO)3, which adopts a perovskite-like architecture. The structural transformation between the C2/c and the P21/c monoclinic phases has a complicated nature and is mainly driven by re-orientational motions of the FA+ cations but it is also accompanied by a significant distortion of the MnO6 octahedral units as well as steric-forced changes of the PH2 groups determining the off-center shifts of FA+ cations in the cages. The re-orientational motions of formamidinium cations at 175K are followed by slight changes of their geometry and re-arrangement of hydrogen bonds (HBs). The strong temperature-dependences of bands corresponding to vibrations involving hydrogen bonding reveal the highly-dynamic character of this phase transition and strong nature of created HBs. The most pronounced changes are observed for the modes corresponding to the formamidinium cation, proving that the phase transition has an order-disorder character.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
