Tetrakis selenourea cobalt II Perchlorate

Co(C104)2-6H20 + 4(NH2)2CSe----- [Co (NH2)2CSe 4](C104)2 + 6H2O 

The complex is obtained as deep olive-green platelike crystals, m.p. 142° (decomposes). The solid compound decomposes slowly on exposure to the atmosphere the process is greatly accelerated if the material is finely divided. The preparation of samples for physical measurements must be carried out in a nitrogen atmosphere. The complex forms very air-sensitive solutions in 1-butanol or nitromethane. The infrared spectrum exhibits characteristic ionic perchlorate absorptions at 1100 and 625 cm, and there are strong ligand bands at 1625, 1400, 575, 500, and 380 cm-i. 

The complex is obtained as relatively air-stable olive-green crystals, m.p. 125°C (decomposes). It may be exposed to the atmosphere for short periods but should be stored under nitrogen. The compound is insoluble in acetone, 1-butanol, methanol, and nitromethane. The monodentate sulfato ligand gives rise to infrared absorptions at 1140(s), 1050 (sh), 970 (w), 640 (m), and 610 (m) cm-i, and there are characteristic selenourea bands at 1640 (s,br), 1510 (m), 1405 (m), 540 (m,br), and 380 (m) cm-.  

Complexes of thiourea with mercury(II) halides have been known for almost a century, and compounds containing one, two, three, or four molecules of coordinated thiourea can be isolated from aqueous solution. With selenourea in acetone, it is possible to prepare 1 2 complexes Hg[(NH2)2CSe]2X2 (X = C, Br, I) and a dimeric 1 1 complex [Hg (NH2)2CSe Cl2]2 in excellent yields. 

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