in benzene (N2); the osmium-compd., the amine and benzene were mixed with magnetic stirring and heated at 40-50°C for 8 h; solvent and excess of amine were removed under reduced pressure, TLC (silica gel, hexane/CH2Cl2 (10:2)), elem. anal.;

in dichloromethane heating (sealed tube, 125°C, 2.5 h), then room temp., overnight; solvent removal (vac.), thin layer chromy. (SiO2, pentane/Et2O=10:1);

in cyclohexane excess of arene was added to hot soln. of Os-complex in cyclohexane; solvent removed under vac., purified by t.l.c. in hexane, yellow band collected;

in neat (no solvent) further products; Os3-cluster suspd. in hexane, solvent evapd., tube evacuated (2h, 10**-3 Torr), sealed, educt pyrolysed (12h, 150-190°C, lesser yield of Os10 cluster at 150-170 °C); extn. of Os5, Os6, Os7, and Os8 cluster with CH2Cl2; extn. of residue with acetone and chromy. of ext. (silica gel, acetone/hexane (1:1)) established Os(CO)12, H2Os(CO)24 and H2Os10(CO)26; cation exchange with Ph4PBr and ClN(PPh3)2 formed cluster salts; slow evapn. of solns. in CH2Cl2/EtOH;

byproducts: Os8(CO)23; vac. pyrolysis of Os-complex at 170°C for 16h; dark brown solid (mixt.), extd. (CHCl2) to remove Os5(CO)16, Os6(CO)18, Os7(CO)21 and Os8(CO)23, residue extd. (acetone) to give dark brown soln. and Os3(CO)12 powder, TLC chromy. of soln. (silica, acetone-hexane 1:1);