in not given react. of Nb(mes)2 and MnCl(CO)5;

in not given react. of Nb(mes)2 and MnI(CO)5;

in toluene treating a suspn. of (FeCp2)BPh4 in toluene with Nb(mes)2, stirring for 24 h at room temp., pptn.; filtn., solid Nb-compd. is dried in vacuo; evapn. of filtrate to dryness and sublimation yields FeCp2;