Highly reduced organometallics 52. Synthesis and chemistry of tricarbonylnitrosylmanganate(2-), [Mn(CO)(3)(NO)](2-)

Treatment of Mn(CO)(3)(NO)(PPh3) in THF at 20 degrees C with excess sodium amalgam, followed by treatment with cryptand 2.2.2, or with two equiv, of p otassium tri-sec-butylborohydride afforded high isolated yields (greater th an or equal to 80%) of air sensitive yellow solids identified as [Na(crypt. 2.2.2)](2)[Mn(CO)(3)(NO)] and K-2[Mn(CO)(3)(NO)], respectively. These produ cts contain the only known mixed carbonylnitrosylmetallate dianion, isoelec tronic with [Fe(CO)(4)](2-) and [Mn(CO)(4)](3-). Reactions of [Mn(CO)(3)(NO )](2-) with Ph3SnCl, Mn(CO)(4)(NO) and Fe(CO)(5), followed by metathesis, p rovided the new derivatives [Et4N][Mn(CO)(3)(NO)(SnPh3)], [PPN](2)[Mn-2(CO) (6)(NO)(2)], and [PPN](2)[MnFe(CO)(7)(NO)]. On the basis of IR spectral dat a the latter two have been formulated to contain non-bridged structures ana logous to that previously established for the isoelectronic salt [PPN](2)[F e-2(CO)(8)]. (C) 2000 Elsevier Science S.A. All rights reserved.