The First Platinum Formyl, a Member of a Series of Hexanuclear Clusters Exhibiting a Rare Structure We thank the Ministero dell'Università e della Ricerca Scientifica e Tecnologica (MURST), Programmi di Interesse Nazionale, 2000–2001, for financial support.

Abstract

The unusual cluster [Pt6(CO)6(μ‐PtBu2)4](CF3SO3)2 (1) has a tetrahedral Pt4 core, two opposite edges of which are bridged by two other platinum atoms (see picture). Complex 1 is remarkably stable and can be regioselectively functionalized at the two apical sites. Its reaction with NaBH4 affords the first platinum formyl complex: [Pt6(CO)4(CHO)2(μ‐PtBu2)4].

Covalent Rigid-Rod Organometallic Polymers with Alternating Transition Metal Clusters and Conjugated Spacers in the Main Chain

“…The 1 H NMR spectra of 3a − c exhibited, besides the aforementioned peaks, a slightly broadened singlet (7.13 ppm) for the aromatic protons, the tert -butyl signal (virtual triplet at 1.51 ppm), and the n -dodecyl resonances (2.76−0.87 ppm), with integral ratios that conform to the proposed structures. The chemical shifts of the 195 Pt{ 1 H} resonances [δ Pt = −4684 (Pt apical ), −2980 (Pt tetrahedron ) ppm] are similar to those reported for {Pt 6 }(CCR) 2 [−4674 (2 Pt), −2996 (4Pt) ppm];8b the complex shape of these resonances is diagnostic for the {Pt 6 } unit symmetrically substituted at the two “apical” positions , and strictly resembles those previously observed for {Pt 6 }X 2 (X = halogen, 8a,b CCR,8b CHO 10 ) and [{Pt 6 }(CO) 2 ] 2+ ,8c for many of which the structure was elucidated by X-ray analysis.…”

“…The reactions were carried out under a nitrogen atmosphere, by using standard Schlenk techniques. [Pt 6 (μ-PBu t 2 ) 4 (CO) 6 ](CF 3 SO 3 ) 2 ( 5 ), Pt 6 (μ-PBu t 2 ) 4 (CO) 4 Cl 2 ( 1 ), and 1,4-didodecyl-2,5-diethynylbenzene ( 2 ) were prepared as previously described. Solvents were dried by conventional methods and distilled under nitrogen prior to use.…”

“…Each Pt 6 cluster is constituted by 22 groups of nonequivalent isotopomers (total number of isotopomers: 2 6 = 64), nearly all giving subspectra that cannot be interpreted with simple first-order approximations, and a meaningful accurate simulation of the total spectrum is not accessible with our programs. However, the main features of the complex shape of the signals remain constant and may be taken as a footprint of the hexanuclear {Pt 6 }X 2 structure. , …”

Stable η1-Alkynyl−μ,η1:η2-Alkenyl Complexes from the Reaction of Terminal Alkynes with Encumbered Dinuclear Platinum Compounds and Their Formyl, Methoxycarbonyl, and Hydride Derivatives

“…Actually, complex 3 reacts with NaBH 4 and CH 3 OLi to give the corresponding acyl derivatives 4 and 5 , respectively. The formyl complex (η 1 -PhCC)(Bu t 2 HP)Pt(μ-PBu t 2 )(μ,η 1 :η 2 -C(Ph)CH 2 )Pt(CHO)(PBu t 2 H) ( 4 ), whose structure was unambiguously confirmed by the spectra of the labeled 13 CHO species ( 4* ), exhibits a remarkably high thermal stability (τ 1/2 (dec) = 5 h); it is worth noting that formyl complexes of platinum were unknown until recently . The methoxycarbonyl compound (η 1 -PhCC)(Bu t 2 HP)Pt(μ-PBu t 2 )(μ,η 1 :η 2 -C(Ph)CH 2 )Pt(COOCH 3 )(PBu t 2 H) ( 5 ) 21 is stable for weeks both in solution and in the solid state.…”

Platinum(II) and Platinum(IV) Acyl and Formyl Complexes

“…Transition-metal formyl complexes have been proposed as intermediates in Fischer−Tropsch syntheses, and their isolation, characterization, and reaction chemistry remain important research targets. − Stable formyl complexes have been described for several late transition metals, including iron, ruthenium, rhodium, and iridium, , but are unknown for platinum monomers. A formyl ligand bound to a platinum cluster has been recently characterized …”