[agris_b]

Please help me! how to synthesize those complex compounds cis and trans [Co(NH3)4Cl2]Cl.
I am not started with trans compound but cis compound synthesis was unlucky for me. I tried synthesis what was in Duval C (1926 year) book from Co(CH3COO)2 and NaNO2 in NH3 solution to prepere
[Co(NH3)4(NO2)2] but all I got was black powderlike substance...
please help me if it is possible

[AWK]

Try other references
http://pubs.acs.org/cgi-bin/abstract.cgi/inocaj/1968/7/i11/f-pdf/f_ic50069a041.pdf?sessid=6006l3