Crystal structure, Hirshfeld surfaces and vibrational studies of tetrachlorocobaltate hybrid perovskite salts NH3(CH2)nNH3CoCl4 (n = 4, 9)

Abstract

Organic-inorganic hybrid perovskites NH3(CH2)nNH3CoCl4 (n = 4, 9) single crystals are prepared by solution precipitation method. Single crystal X-ray diffractions are performed. Both compounds crystallized in the centrosymmetric triclinic P-1 (Z = 2) space group; the determined parametrs for the novel salt NH3(CH2)9NH3CoCl4 are: a = 7.3113(4) Å, b = 10.2373(5) Å, c = 12.4701(9) Å; α = 112.323(2)°, β = 92.441(2)°, γ = 93.452(3)°, V = 859.68(9) Å3. The structure consists of the anions CoCl42− which form unassociated zero dimensional tetrahedral structure resemble to quantum dot show alternating up and down orientations relative to the c-axis that are sandwitched between layers of the diammonium organic chains. Hydrogen bonds NH…Cl are connecting organic and inorganic layer. The Hirshfeld surface analyzes are performed to compare the importance of hydrogen bonding contacts in the two hybrid compounds. The V/Z ratio on linear evolution versus n, number of CH2 groups in organic chains (n = 3–9) presents a minimal value at n = 5, corresponding to monoclinic symmetry of NH3(CH2)5NH3CoCl4. Besides, the vibrational modes analyzes are developed based on the theoretical group method considering the structural data obtained on +NH3(CH2)nNH3+ cations and CoCl42− anions. This to study the characteristic bands observed at room temperature in Infrared (250–4000 cm−1) and Raman (50–500 cm−1) spectra of these compounds.