Anionic Tetranuclear Platina-β-diketonates of Platina-β-diketones – Organometallic Analogues of Platinum Blue Complexes

Abstract

The platina‐β‐diketone [Pt2{(COMe)2H}2(μ‐Cl)2] (1) reacts with aliphatic amines [nBuNH2, (iPr)2NH, NEt3], N‐methylaniline, and N,N‐dimethylaniline, as well as with strong bases, such as a proton sponge or [NMe4]OH, in an equimolar ratio to give the anionic platina‐β‐diketonato complexes of platina‐β‐diketones [BH]2[{Cl2Pt(μ‐COMe)2Pt[(COMe)2H]}2] (3) {B = nBuNH2 (3a), (iPr)2NH (3b), NEt3 (3c), PhNHMe (3d), PhNMe2 (3e), C10H6(NMe2)2 [1,8‐bis(dimethylamino)naphthalene] (3f) and [NMe4]2[{Cl2Pt(μ‐COMe)2Pt[(COMe)2H]}2] (3g)}. All complexes were characterized by microanalysis, and by 1H‐NMR and IR spectroscopy. X‐ray structure analyses reveal that in the solid state the complexes 3a · 0.5 CH2Cl2 and 3g · 2 CH2Cl2 consist of tetranuclear dianions with zigzag Pt4 chains [Pt–Pt–Pt angle: 122.92(3)° (3a), 119.30(6)° (3g)]. The central Pt···Pt distances [3a: 3.171(1) Å, 3g: 3.176(1) Å] give evidence for closed shell d8‐d8 interactions. Thus, these bis(acyl)‐bridged complexes can be regarded as organometallic analogues of platinum blue complexes.

Reactions of Platina-β-diketones with 2-Aminopyridines: Synthesis and Characterization of Aminocarbene Complexes of Platinum(II)

“…This is why complex 1 exhibits an entirely different reactivity than Lukehart's mononuclear metalla-β-diketones [L x M{(COR) 2 H}] ( 2 ) (L = CO, Cp; M = Mo, Re, Fe, ...; R = alkyl, aryl), which are electronically saturated (18 ve) and kinetically stable complexes . The pronounced different reactivity is demonstrated in Scheme in reactions with amines, affording in the case of complex 1 platina-β-diketonates of platina-β-diketones . On the other hand Lukehart's metalla-β-diketones 2 were found to react with amines analogously to Fischer carbene complexes with formation of metalla-β-ketoimines (Scheme ) …”

Reactivity of Platina-β-diketones with 1,4-Diazabuta-1,3-dienes: Synthesis and Characterization of Acylplatinum(II) Complexes with RNCMeCMeNR and RN(H)CHCHN(R)C(O)Me Ligands

“…Platina-β-diketones 1 exhibit unique reactivity. The methyl-substituted complex 1a (R = Me) reacts (Scheme ) (i) with amines and other bases, yielding platina-β-diketonates of platina-β-diketones that can be regarded as organometallic analogues of platinum blues, (ii) with pyridines and quinoline, yielding mononuclear platina-β-diketones, and (iii) with phosphines and diphosphines, yielding acylplatinum(II) complexes with cleavage of acetaldehyde . Reactions (iv) with bipyridines and phenanthrolines resulted in formation of hydrido(acetyl)-platinum(IV) complexes that exhibited an astonishing thermal stability.…”

Reactivity of Quinoline-8-carbaldehyde toward Platina-β-diketone and Acetyl(amine)platinum(II) Complexes. Formation of Acyl(hydroxyalkyl)platinum(IV)

“…The signals at lower wavenumbers (1499, 1512 cm –1 ) are in accord with the presence of bridging acyl groups . Bridging acetyl ligands in platina-β-diketonates of platina-β-diketones show absorptions in the 1514–1534 cm –1 range . The signal at 1629 cm –1 can be assigned to terminal acyl groups.…”

“…The bond distances involving the metal are as expected, and the C–O bond lengths are equal within the 3σ criterion, regardless of the acyl groups belonging to an acetyl bridge (mean 1.25(2) Å) or to a terminal chelating ligand (mean 1.22(2) Å). The coordination planes are bent at an angle of 102.2(6)°, larger than in the related platina-β-diketonates of platina-β-diketones [{X 2 Pt(μ-COMe) 2 Pt{(COMe) 2 H}} 2 ] z (X/X = Cl/NH 2 Ph′, z = 0; X/X = Cl/Cl, z = 2–; X/X = bpy, z = 2+) with a head-to-head arrangement of the bridging acetyl ligands, where the angles are 76.3(4)–89.6(4)°. , The platinum–platinum distances, Pt1···Pt2 = 3.462(1) Å for 4A and Pt3···Pt4 = 3.438(1) Å for 4B , are longer than those in platina-β-diketonates of platina-β-diketones (3.160(1)–3.358(1) Å). Two kinds of intermolecular interactions can be detected.…”