Synthesis, crystal structures, thermal, magnetic and luminescence properties of Mn(II) and Cd(II) thiocyanate coordination compounds with 4-(Boc-amino)pyridine as co-ligand

Reaction of Mn(NCS)2 and Cd(NCS)2 with 4-(Boc-amino)pyridine leads to the formation of compounds of composition M(NCS)2(4-(Boc-amino)pyridine)4 (M = Mn, 1-Mn; Cd, 1-Cd) and (M(NCS)2(4-(Boc-amino)pyridine)2 (M = Mn, 2-Mn; Cd, 2-Cd). 1-Cd and 1-Mn, respectively 2-Cd and 2-Mn are isotypic and their structures were determined by X-ray single crystal or powder diffraction. 1-Mn and 1-Cd consist of discrete complexes, whereas in 2-Mn and 2-Cd the cations are linked into chains by μ-1,3-bridging anionic ligands. On heating 1-Cd and 1-Mn, mass steps are observed that indicate formation of compounds of composition M(NCS)2(4-(Boc-amino)pyridine)2, but ex-situ XRPD investigations prove that amorphous intermediates are obtained. In contrast, temperature dependent XRPD measurements for 1-Cd indicate the formation of an unknown crystalline phase. Magnetic measurements on 2-Mn show dominating antiferromagnetic interactions along the chain and at TN = 22.0 K antiferromagnetic ordering is observed. 1-Cd and 2-Cd show bluish ligand-based luminescence with emission maxima at, respectively 22,301 cm−1 and 20,678 cm−1, while 1-Mn and 2-Mn present metal-based luminescence in the yellow spectral range with emission maxima at 18,382 cm−1.