Lanthanide phosphine complex

The discussion of the activation of bonds containing a group 15 element is continued in chapter five. D.K. Wicht and D.S. Glueck discuss the addition of phosphines, R2P-H, phosphites, (R0)2P(=0)H, and phosphine oxides R2P(=0)H to unsaturated substrates. Although the addition of P-H bonds can be sometimes achieved directly, the transition metal-catalyzed reaction is usually faster and may proceed with a different stereochemistry. As in hydrosilylations, palladium and platinum complexes are frequently employed as catalyst precursors for P-H additions to unsaturated hydrocarbons, but (chiral) lanthanide complexes were used with great success for the (enantioselective) addition to heteropolar double bond systems, such as aldehydes and imines whereby pharmaceutically valuable a-hydroxy or a-amino phosphonates were obtained efficiently. 

Charbonniere, L. J. Ziessel, R. Montalti, M. Prodi, L. Zaccheroni, N. Boehme, C. Wipff, G. Luminescent lanthanide complexes of a bis-bipyridine-phosphine-oxide ligand as tools for anion detection. J. Am. Chem. Soc. 2002, 724(26), 7779-7788. 

In principle, lanthanide complexes of alkyl- (phosphinates) or alkoxy- (phosphonate esters) DOTP derivatives may give rise to 32 stereoisomers, existing as 16 enantiomeric pairs, which are indistinguishable by NMR spectroscopy. The isomers originate from chiral elements inherent in these complexes, including the R or S configuration at each phosphorus and the helicity defined by the pendant arm orientations (AIA). Various Ln3+ complexes of phosphinate and phosphonate ester ligands derived from 1,4,7,10-tetraazacyclododecane (cyclen) have been described in the literature [104-107]. 

Introducing a chiral center in the amide functionality renders all 32 potential isomers diastereomeric and thus discernable (in principle) by NMR spectroscopy. In practice, the lanthanide complexes formed (Eu, Gd and Tb) with macrocyclic monoamide tris(phosphinate) ligands bearing a chiral center on the amide group exist as only two non-interconverting diastereomers in a ratio of 2 1 and 4 1 for the a-phenylethyl and a-l-napthylethyl derivatives, respectively (DOTMP-MPMeA and DOTMP-MNaphMeA) [114]. The configuration at... 

There is an isolated example in which phosphine selenides and tellurides transfer selenium or tellurium to unsaturated lanthanide complexes to form bridging dimers [263]. 

Apart from the compounds already mentioned, vanadium, manganese, and cobalt chlorides, tetra-alkoxy derivatives of titanium, acetylacetonates of V, Cr, Mo, Mn, and Ni, Cp derivatives of Zr and Nb, and triphenyl phosphine complexes of Ti and Fe were found to be active. Later lanthanide complexes were included in the list of dinitrogen-reducing systems, the most effective being compounds of samarium and yttrium. 

K. Inaba, S. Murahdharan, and H. Freiser, Simultane-ons characterization of extraction eqnilibria and back-extraction kinetics Use of arsenazo III to characterize lanthanide-bis(2,4,4-trimethylpentyl)phosphinic acid complexes in surfactant micelles. Anal. Chem. 65 1510 (1993). 

Phosphine Chalcogenides as Ligands. - The complexation of lanthanide and actinide ions by phosphine oxide ligands remains an active area, and a theoretical assessment of the coordination of phosphine oxides (and phosphate esters) by trivalent lanthanide ions has appeared." Trivalent lanthanide complexes of the functionalised enol phosphine oxide (265), (and a related phosphonate), have been describedComplexes of thorium(iv) with bis(di-phenylphosphino) ethane dioxide and bis(diphenylphosphinoyl)amide have also been characterised." Calixarene systems which bear phosphine oxide... 

CCC (1987) contains a section on sulfoxides, amide, amine oxides, and related ligands that have sections on phosphine oxides and arsine oxides.159 Phosphine and arsine oxide complexes of yttrium and the lanthanides were highlighted in CCC (1987).1 Scandium and yttrium phosphine oxide complexes have been reinvestigated and characterized by multinuclear NMR and X-ray... 

C 4H gOgP, 1/7-Phospholium, 2,3,4,5-tetra-kis(methoxycarbonyl)-2,2-dimethyl-, manganese complex, 26 167 C,4H2QOgPS. 2W-l,2-Thiaphosphorin-2-ium, 3,4,5,6-tetrakis(methoxycaibonyl)-2,2-dimethyl-, manganese complex 26 165 C,4H720, Phenol, 2,6-di-terr-butyl-, actinide and lanthanide complexes, 27 166 C HjjP, Phosphine, di-rm-butylphenyl-, palladium and platinum complexes, 28 114, 116... 

Platinum catalysts of the preceding section activate only the nucleophile (a secondary phosphine), which then reacts with the electrophile (an activated alkene). There are, however, interesting examples of lanthanide complexes activating both the nucleophile and the electrophile towards intramolecular diastereoselective hydrophosphination/cyclisations. In 2000 Marks and co-workers found that certain lanthanide complexes catalyse the intramolecular hydrophosphination of alkenes and alkynes (Scheme 6.13). 

In this thesis, the control of coordination structures and functionalization of luminescent lanthanide(lll) complexes with LVF hfa and phosphine oxide ligands were investigated. In particular, the author constructed (1) lanthanide coordination polymer with thermostability and thermosensing ability and (2) lanthanide complexes with novel asymmetric coordination structures to improve their emission quantum yields. 

Here, the author considers that the introduction of low-vibrational frequency (LVF) ligands as a linker part in the polymer chains would result in the preparation of a lanthanide coordination polymer with strong luminescence properties. Strongly liuninescent lanthanide complexes composed of LVF hfa and bidentate phosphine oxide ligands have been described in former chapters. The author also proposes that the introduction of aromatic aryl groups in the linker part of lanthanide coordination polymer is effective for the construction of thermostable luminophores with intermolecular interactions, such as CH/F, n-n, and CWn interactions. 

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