Thermal Transformations of Platinum‐Heterobimetallic Iminodiacetate Dithiocarbamates Comprising Group 2 and Group 12 Metal Ions

The thermal decomposition of the compounds M 2 [Pt(L) 2 ] (M = Ca, Sr, Ba, Zn, Cd; L = N ‐dithioato‐iminodiacetate) was investigated by thermogravimetry and powder X‐ray diffraction. The pristine hydrated compounds can be fully dehydrated by heating without decomposition. Structural elucidation of Ca 2 [Pt(L) 2 ]·4H 2 O and Zn 2 [Pt(L) 2 ]·8H 2 O·3 acetone was performed by single‐crystal X‐ray diffraction, whereas the structures of Ba 2 [Pt(L) 2 ]·2H 2 O, anhydrous Ba 2 [Pt(L) 2 ], Zn 2 [Pt(L) 2 ]·2H 2 O, and Cd 2 [Pt(L) 2 ]·2H 2 O were determined from powder X‐ray diffraction data. The Ca, Sr, and Ba compounds form ionic 3D networks with irregular coordination environment of the alkaline‐earth metal center, whereas the Zn and Cd compounds display a more regular five‐ or six‐coordination by oxygen donors. The pristine hydrates form crystallites with diameters in the lower µm range. Combustion at 600°C results in the formation of crystalline MSO 4 (for M = Ca, Sr, Ba), Zn 3 O(SO 4 ) 2 , or CdSO 4 /CdO mixture. For Zn, further heating to 1000°C yields ZnO, whereas CdO sublimes under these conditions. The combustion products retain their original particle morphology for the alkaline‐earth derivatives, whereas they are not mechanically stable in the Zn and Cd cases. For the particles formed at 600°C, a homogenic distribution of nanocrystalline platinum is assumed, sintering to larger spherical particles in the 100 nm diameter range upon heating to 1000°C.