Rhodium nanoparticles stabilized by ferrocenyl-phosphine ligands: synthesis and catalytic styrene hydrogenation

A series of ferrocenylphosphine-stabilized rhodium nanoparticles has been prepared in one pot from the organometallic [Rh(η3-C3H5)3] precursor. This complex has been decomposed by hydrogen treatment (3 bar) in dichloromethane in the presence of five different ferrocene-based phosphine ligands. Very small rhodium nanoparticles in the size range of 1.1-1.7 nm have been obtained. These nanoparticles have shown activity in a model catalytic reaction, namely the hydrogenation of styrene. These results evidence that the metal surface is not blocked despite the steric bulk of the stabilizing ligands. Moreover, certain selectivity has been observed depending on the ligand employed. To the best of our knowledge, such a type of compound has not yet been used for stabilizing metal nanoparticles and our findings highlight the interest to do so.

Novel enantiopure monophospholes: synthesis, spatial and electronic structure, photophysical characteristics and conjugation effects

A rational and highly efficient method to access lithium 2,3,4,5-tetraphenylphospholide directly from white phosphorus, diphenylacetylene and lithium has been developed.

New Ferrocenyl Phenol Thiophosphines

Two new enantiomerically pure ferrocenyl phenol-thiophosphine compounds have been efficiently synthesized by a one pot procedure from enantiomerically pure alcohol (R)-(diphenylthiophosphinoferrocenyl)methanol 1 by a fully regioselective Friedel-Crafts reaction on phenols after strong acid activation. A mechanistic proposal through O-alkylation followed by rearrangement of the formed oxonium is proposed. All compounds have been and fully characterized by NMR(1H, 31P and 13C) and High Resolution Mass Spectroscopy. The molecular structure of one of these ferrocene derivatives have been determined by X ray diffraction analysis on monocrystal.

A Ferrocenyl-Backboned Unsymmetric O,C-Coordinating Ligand and Its Tin Derivatives

The syntheses of the phosphonyl-substituted ferrocenyl stannane Fe[{η (5)-C5H3-1-SnPh3-2-P(O)(O-iPr)2}{η (5)-C5H4P(O)(O-iPr)2}] (1) and its iodine derivative Fe[{η (5)-C5H3-1-SnPh2I-2-P(O)(O-iPr)2}{η (5)-C5H4P(O)(O-iPr)2}] (2) are reported. The syntheses of the corresponding salts Fe[{η (5)-C5H3-1-SnPh2-2-P(O)(O-iPr)2}{η (5)-C5H4P(O)(O-iPr)2}]X (3, X=Al{OC(CF3)3}4, 4, X=ClO4, 5, X=HgI3), respectively, are also described. The compounds are characterized by elemental analyses, (1)H, (13)C, (31)P, (119)Sn NMR and IR spectroscopy, electrospray ionization mass spectrometry, and, except for 4 and 5, single-crystal X-ray diffraction analyses.

Different Complexation Behavior of P-Functionalized Ferrocene Derivatives Towards SnCl2 , SnCl4 and SnPh2 Cl2 : Auto-ionization and Redox-Type Reactions

The novel phosphonyl-substituted ferrocene derivatives [Fe(η(5) -Cp)(η(5) -C5 H3 {P(O)(O-iPr)2 }2 -1,2)] (Fc(1,2) ) and [Fe{η(5) -C5 H4 P(O)(O-iPr)2 }2 ] (Fc(1,1') ) react with SnCl2 , SnCl4 , and SnPh2 Cl2 , giving the corresponding complexes [(Fc(1,2) )2 SnCl][SnCl3 ] (1), [{(Fc(1,1') )SnCl2 }n ] (2), [(Fc(1,1') )SnCl4 ] (3), [{(Fc(1,1') )SnPh2 Cl2 }n ] (4), and [(Fc(1,2) )SnCl4 ] (5), respectively. The compounds are characterized by elemental analyses, (1) H, (13) C, (31) P, (119) Sn NMR and IR spectroscopy, (31) P and (119) Sn CP-MAS NMR spectroscopy, cyclovoltammetry, electrospray ionization mass spectrometry, and single-crystal as well as powder X-ray diffraction analyses. The experimental work is accompanied by DFT calculations, which help to shed light on the origin for the different reaction behavior of Fc(1,1') and Fc(1,2) towards tin(II) chloride.

New Ferrocene Derivatives for Ligand Grafting

Five new 1,2-disubstituted ferrocene derivatives have been efficiently synthesized. These compounds contain one protected phosphine function as thiophosphine, another coordination site (nitrogen or oxygen atom) and a function ready for the grafting on various supports. All compounds have been and fully characterized by NMR(1H, 31P and 13C) and High Resolution Mass Spectroscopy. The molecular structure of three of these ferrocene derivatives have been determined by X ray diffraction analysis on monocrystals.

Phosphole-based ligands in catalysis

This review provides an overview of phosphole-based ligand families (monophospholes, multidentate hybrid phosphole ligands, diphosphole and 2,2′-biphosphole-based ligands) and their potential in metal- and organo-catalyzed reactions (asymmetric reactions included).

Chiral and extended π-conjugated bis(2-pyridyl)phospholes as assembling N,P,N pincers for coordination-driven synthesis of supramolecular [2,2]paracyclophane analogues

Chiral, π-conjugated 3,4-butano-1-phenyl-2,5-bis(2-pyridyl)phosphole derivatives 1a(2,2') and 1a(3) with chiral trans-1,2-diol moieties and fused pinene derivatives, respectively, were prepared from the corresponding chiral diynes by using the Fagan-Nugent method. Their UV/Vis absorption and chiroptical properties (optical rotation and circular dichroism) were studied. Their behavior as N,P,N chelates towards coordination of Cu(I) and formation of chiral supramolecular assemblies with π-conjugated ditopic dicyano ligands was investigated. Chiral C(2)-symmetric rectangles that are [2,2]paracyclophane analogues were obtained, as demonstrated by X-ray crystallography. During the course of this study, the first stable water-soluble phosphole derivative (1a(2)·2 HCl) was prepared. Furthermore, achiral 3,4-butano-1-phenyl-2,5-bis(aza[4]helicene)phosphole 1a(4) was synthesized and displays extended π conjugation. A supramolecular rectangle was obtained by coordination to Cu(I) and assembly with a dicyano stilbene. This coordination-driven supramolecular assembly contains a total of four aza[4]helicene moieties and displays two types of π-π stacking interactions in the solid state, that is, between two helicene moieties and between one helicene and a bridging dicyano ligand. All the supramolecular arrangements are discussed by comparing them with previous work on the parent 3,4-butano-1-phenyl-2,5-bis(2-pyridyl)phosphole.