Structural, phonon, magnetic and optical properties of novel perovskite-like frameworks of TriBuMe[M(dca) 3 ] (TriBuMe = tributylmethylammonium; dca = dicyanamide; M = Mn 2+ , Fe 2+ , Co 2+ , Ni 2+ )

for TriBuMeNi), suggesting that these compounds might be promising barocaloric materials. Raman and IR data confirm the same monoclinic structures for all compounds and show that all changes on heating to 430-450 K are reversible after cooling the samples to room temperature. Magnetic studies indicate that all studied compounds are paramagnets at least down to 2 K. Optical studies indicate that TriBuMeMn has an energy band gap of 4.95 eV and exhibits orange emission under 420 nm excitation with the activation energy for thermal quenching of 0.0673 eV.