Osmium formaldehyde complex

This osmium formaldehyde complex reacts with CSc2 to first insert then eliminate COSe. 

Roper has been able to isolate another osmium formyl by rearrangement of an rj2-formaldehyde complex, as shown in Eq. (9) (54). Because of the unavailability of such precursors, this reaction also does not provide a general entry into neutral formyl complexes. However, Eq. (9) does lend support to the claim that the related ruthenium formyl, Ru(H)(solv) (PPh3)3(CHO) (40), can be isolated as an impure solid, contaminated with substantial quantities of an rf -formaldehyde precursor (55). 

Oxidative addition to ruthenium and osmium four-coordinate complexes occurs readily. These complexes are excellent starting materials for group VIII complexes. Addition of formaldehyde to complexes M(CO)L(PPh3)2 (L = CO or PPhs selection of L is metal dependent) leads to oxidative addition products, a reaction of relevance to Fischer-Tropsch processes. The ruthenium complex is proposed as an intermediate only the osmium complex has been isolated ... 

Platinum (Pt, at. mass 195.09) occurs in its compounds in the II and IV oxidation states, compounds of Pt(IV) being the more stable. The hydroxide Pt(OH)4 dissolves in excess of NaOH. Platinum(IV) forms chloride, iodide, cyanide, and nitrite complexes. Platinum(II) and -(rV) are more difficult to reduce to the metal than is gold(ni). Zinc and aluminium in acid solution, and formaldehyde in an alkaline medium, are suitable reductants. Of the other platinum metals, palladium resembles platinum most closely, and osmium and ruthenium resemble it least. 

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