Synthesis, Characterization, and Electrochemistry of Compounds Containing 1-Diphenylphosphino-1′-(di-tert-butylphosphino)ferrocene (dppdtbpf)

Abstract

The anodic electrochemistry of 1-di-tert-butylphosphino-1′-diphenylphosphinoferrocene (dppdtbpf) was performed in methylene chloride with tetrabutlylammonium hexafluorophosphate as the supporting electrolyte. The electrochemistry is complicated by a chemical reaction after the oxidation. Three new transition metal complexes of dppdtbpf ([NiCl 2 (dppdtbpf)], [PtCl 2 (dppdtbpf)], and [Au 2 Cl 2 (dppdtbpf)]) were prepared and characterized. The electrochemistry of the three new compounds and one previously prepared compound ([PdCl 2 (dppdtbpf)]) was examined. In addition, the reaction of dppdtbpf with sulfur and/or selenium afforded a series of compounds containing a phosphine sulfide (dppSdtbpSf or dppdtbpSf), a phosphine selenide (dppSedtbpSef or dppdtbpSef), or both a phosphine sulfide and a phosphine selenide (dppSedtbpSf or dppSdtbpSef). These compounds were characterized by NMR, and the structures of three of the compounds were determined. Two of the structures are of the isomeric compounds, dppSdtbpSef and dppSedtbpSf, in which the sulfur and selenium atoms are switched between the two different phosphine groups. The anodic electrochemistry of these sulfur-and/or selenium-containing compounds was examined in methylene chloride. The potentials at which oxidation occurs are more positive than those of the free phosphine. Nearly all of the oxidations are complicated by at least one chemical reaction.

Late Transition Metal Compounds with 1,1′‐Bis(phosphino)ferrocene Ligands

“…0.24 V more positive than the waves for free 3 (0.06 V) [9] and 4 (0.11 V). [10] This behavior is similar to that reported for the analogues 1 [2] and 2. [3] The irreversibility of the oxidation of the zinc compounds has been attributed to the cleavage of the purely P-Zn σ-bond upon oxidation to form free [bis(phosphino)ferrocene] + species, which undergo quick decomposition reactions.…”

“…The compounds were synthesized by adding the appropriate Table 2. Similarly to those of the phosphine oxides, the P-S bond in 4S (P-S 1.9701 Å) [10] lengthens upon coordination to the zinc atom. The Zn-P bond is slightly shorter in [Zn(4S)Cl 2 ] than in [Zn(4)Cl 2 ] (vide supra).…”

“…[10] In addition to the zinc compounds, a series of gold compounds were also examined. The electrochemical oxidations of [(AuCl) 2 (1)], [10] [(AuCl) 2 (3)], [10] and [(AuCl) 2 (4)] [9] in CH 2 Cl 2 were examined previously, and they all display a single reversible wave. In another report on the oxidation of [(AuCl) 2 (1)] in N,Ndimethylformamide, no electrochemical oxidation was observed.…”

“…The phosphine chalcogenide ligands 1O 2 , [40] 4S, [10] and 4S2; [10] the gold compounds [(AuCl) 2 (1)], [8] [(AuCl) 2 (3)], [9] and [(AuCl) 2 (4)]; [10] 4 ] were obtained at room temperature by vapor diffusion of diethyl ether into a solution of each compound in CH 2 Cl 2 . Single crystals were selected and mounted with NVH immersion oil onto a nylon fiber and cooled to the data-collection temperature of 100(2) K with a stream of dry nitrogen gas.…”

“…The oxidative electrochemical behaviors of the 1, [10] 2, [3] 3, [9] 4, [10] 5, [4] and 1,1′-bis(dimethylaminophosphino)ferrocene [12] compounds have been examined, and they exhibited reversible waves, presumably owing to oxidation at the iron center. However, the chemical oxidation of [(AuCl) 2 (1)] led to a product that did not contain Fe III .…”