38897-83-5Relevant articles and documents
The influence of steric bulk on the geometry of triarylphosphite-based palladacycles and their tricyclohexylphosphine adducts
Bedford, Robin B.,Betham, Michael,Coles, Simon J.,Horton, Peter N.,López-Sáez, María-José
, p. 1003 - 1010 (2008/10/09)
A range of complexes of the formula [PdCl2{P(OAr) 3}2] have been synthesized in order to determine the effect of steric bulk on stereochemistry, one example [PdCl 2{P(OC6H4-2-tBu)3} 2] has been structurally characterized. Three palladacyclic complexes [{Pd(μ-Cl)(κ2-P,C-P(OC6H3R)(OC 6H4R)2)}2] have been synthesized (R = H, 2-iPr, 2-tBu) and two have been characterized by crystallography (R = H and tBu). The latter adopts the expected trans geometry while the former is cis. In this case, the driving force for the cis geometry seems to be intermolecular interactions in the crystal structure which are disrupted on substitution. We also report an unusual solvolysis reaction.
Calix[4]arene derived phosphites: Their hydrolytic stability and complexes with gold(I), platinum(II,0), palladium(II) and iridium(I)
Cobley, Christopher J.,Ellis, Dianne D.,Guy Orpcn,Pringle, Paul G.
, p. 1101 - 1107 (2007/10/03)
Improved syntheses of the monophosphites La and Lb derived from calix[4]arene and p-tert-butylcalix[4]arene respectively are reported. Both La and Lb are thermally stable and air stable even in refluxing toluene; moreover they are not hydrolysed by aqueous HC1 or NaOH. The two-coordinate gold(i) complexes [AuCl(La)] and [AuCl(Lb)] are readily made from [AuCl(tht)](tht = tetrahydrothiophene). Treatment of K[PtCl3(C2H4)] with La gives the mononuclear cis-[PtCl2(La)2] whereas Lb gives the binuclear trans-[Pt2Cl2(μ-Cl)2(Lb) 2]. The platinum(O) complexes [Pt(L)-(nor)2] and [Pt(L)2(nor)](L = La or Lb, nor = norbornene) have been characterised in solution by 31P and 195Pt NMR spectroscopy. Treatment of [PdCl2(NCPh)2] with La gives a poorly soluble complex assigned the structure [PdCI2(La)2]. Treatment of [PdCl2(NCPh)2] with Lb gives the binuclear [Pd2Cl2(μ-Cl)2(Lb)2] which reacts with Y to give bridge-cleaved products [PdCl2(Y)(La)](Y = CO, CNBut or CNMe). The iridium complexes [IrCl(La)(cod)] and [IrCI(Lb)(cod)] are made by the additions of La or Lb to [Ir2(μ-Cl)2(cod)2]. The crystal structures of [Pt2Q2-(μ-Cl)2(Lb)2], [Pd2Cl2(μ-Cl)2(Lb)2], [PdCl2(CNBut)(Lb)] and [IrCI(La)(cod)] have been determined. The calixarene conformation in all cases has arenes in {down, out, up, up} orientations with one aryl blocking an axial site at the square planar metal. The cone angles are 160° for Lx and 176° for Lb. The bulkiness of the ligand is such as to preclude octahedral geometry at the metal. The trans influence of the ligands La and Lb appear to be greater than either chloride or isocyanide. The P-O distances and the O-P-O angles imply that La and Lx are less π-acidic than most triarylphosphite ligands. The Royal Society of Chemistry 2000.
Synthesis and NMR spectroscopy of cyclopalladated tertiary phosphite complexes. X-ray crystal structure of Pd(η5-C5H5)(P(OPh)2(OC6H4))
Albinati,Affolter,Pregosin
, p. 379 - 387 (2008/10/08)
The paper reports the authors' initial studies on the cyclometalation and characterization of complexes derived from P(OPh)3 and P(OEt)2(OPh), with the latter ligand selected so that after cyclometalation and subsequent transformation (e.g., carbonylation), hydrolysis would readily yield the ortho-substituted phenol. For comparison purposes the authors have also prepared and cyclopalladated P(OEt)2(NMePh), an N-methylaniline analog. In the course of this work, the crystal structure of Pd(η5-C5H5)(P(OPh)2(OC6H4)) was determined and found to contain some interesting features, which are discussed as well.
