Sinteza in karakterizacija hidroksilamonijevega fluorokromata

Reactions in the system $Cr – NH_3OHF – HF – H_2O$ were investigated. Green crystals of a new compound with the formula $(NH_3OH)_3CrF_6$ have been isolated from the water solution and characterized by chemical analysis. The compound crystallizes as triclinic, P-1, with cell parameters: a = 6.5461(2) Å, b = 6.9347(2) Å, c = 9.4072(3) Å, α = 86.772(1)°, β = 83.804(1)°, γ = 70.283(1)°. The effective magnetic moment, $µ_{eff}$ = 3.82 BM, was calculated from magnetic susceptibility measurements in the temperature range 80-290 K. The thermal decomposition of the compound was studied by TG and DSC analysis. $(NH_3OH)_3CrF_6$ decomposes above 125 °C in three steps and the residue has been identified by X-ray powder diffraction as $α – Cr_2O_3$.Raziskovali smo reakcije v sistemu $Cr – NH_3OHF – HF – H_2O$. Iz vodne raztopine smo izločili zelene kristale nove spojine in s kemijsko analizo določili formulo $(NH_3OH)_3CrF_6$. Spojina kristalizira triklinsko, P-1, s parametri osnovne celice: a = 6.5461(2) Å, b = 6.9347(2) Å, c = 9.4072(3) Å, α = 86.772(1)°, β = 83.804(1)°, γ = 70.283(1)°. Iz meritev magnetne susceptibilnosti v območju 80-290 K smo izračunali efektivni magnetni moment, $µ_{ef}$ = 3.82 BM. S termogravimetričnimi in diferencialno termičnimi meritvami smo spremljali termični razkroj spojine. $(NH_3OH)_3CrF_6$ nad temperaturo 125 °C razpada v treh stopnjah, pri čemer smo končni preostanek identificirali z rentgenskimi praškovnimi meritvami kot $α – Cr_2O_3$