Crystal structure, vibrational spectra, optical properties and thermal behavior of the 1D perovskite (2-amino-4-methylpyridinium)trichlorocadmate(II) (C₆H₉N₂)¹_∞[CdCl₃]

Abstract

The organic-inorganic hybrid compound (2-amino-4-methylpyridinium) trichlorocadmate(II), (C₆H₉N₂)¹_∞[CdCl₃] was prepared in crystalline form by solvent evaporation at room temperature. Infrared and Raman spectra allowed tracing the entities of the organic aromatic cation and the inorganic ¹_∞CdCl_n scaffold. X-ray diffraction showed that the compound crystallizes in the orthorhombic system in the centrosymmetric space group Pnma and has a one-dimensional (1 D) perovskite structure. Hirshfeld surface analyses (d_norm and shape index) of the studied structure, as well as its fingerprints, allowed us to identify and quantify the intermolecular interactions such as H bonds and π stacking. UV-visible absorption spectroscopy allowed us to estimate the direct band gap using the Tauc-extrapolation method. From this, we conclude a semiconducting character of the compound with a band gap of about 3.5 eV. Photoluminescence was observed with maxima at 351 and 388 nm when excited at 312 nm and can be traced to excited π–π* states in the organic cation. Thermogravimetric and differential thermal analysis showed that the compound is stable up to 200 °C and decomposes stepwise.

KEYWORDS:

• 1D-perovskite
• crystal structure
• pyridinium cadmate
• UV-vis absorption
• thermal analysis

Supplementary material

CCDC 2057077 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge at www.ccdc.cam.ac.uk/conts/retrieving.html or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge, CB2 1EZ UK. Fax: [phone]; E-mail: [email protected].

The infrared spectrum (Figure S1), the Raman spectrum (Figure S2), the UV-vis absorption spectrum (Figure S3), plots of the curves [F(R_d)hν]^1/2 and [F(R_d)hν]² (Figure S4), the photoluminescence spectrum (Figure S5) and the TG and DTA curves of (C₆H₉N₂)[CdCl₃] (Figure S6) are provided in the Supporting Information.

Disclosure statement

No potential conflict of interest was reported by the authors.