Synthesis and reactivity of α-cationic phosphines: the effect of imidazolinium and amidinium substituents.

Mono- and dicationic phosphines have been synthesized through the reaction of chloroimidazolinium or chloroamidinium salts with secondary or primary phosphines respectively. The resulting ligands, which depict a significantly reduced donor ability compared with their neutral analogues, have been used to design Pt(II) and Au(I) complexes that effectively catalyse the hydroarylation of alkynes.

Bis[(dialkylamino)cyclopropenimine]-Stabilized P(III) - and P(V) -Centered Dications.

The treatment of bis[(dialkylamino)cyclopropenimines] with dihalophosphines in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) to form diimine-stabilized P(III) -centered dications is reported. The structures of the new compounds were determined by using X-ray diffraction analysis and their donor abilities as ligands evaluated through electrochemical methods. Despite the two positive charges that they bear, these compounds depict intermediate behavior between that of phosphines and phosphites. The coordination of the [L2 PR](2+) moiety to Au(I) and Ag(I) is also reported. Even more surprisingly, these phosphorus centers can be oxidized to the corresponding P(V) dications in the presence of strong oxidants such as peroxides or XeF2 .

Coordination chemistry of cyclopropenylidene-stabilized phosphenium cations: synthesis and reactivity of Pd and Pt complexes.

A straightforward synthesis of cyclopropenylidene-stabilized phosphenium cations 1 a-g through the reaction of [(iPr2N)2C3(+)Cl]BF4 with secondary phosphines is described. Their donor ability was evaluated by analysis of the CO stretching frequency in Rh complexes [RhCl(CO)L2](BF4)2 and electrochemical methods. The cyclopropenium ring induces a phosphite-type behavior that can be tuned by the other two substituents attached to the phosphorus atom. Despite of the positive charge that they bear, phosphenium cations 1 a-g still act as two-electron donor ligands, forming adducts with Pd(II) and Pt(II) precursors. Conversely, in the presence of Pd(0) species, an oxidative insertion of the Pd atom into the Ccarbene-phosphorus bond takes place, providing dimeric structures in which each Pd atom is bonded to a cyclopropenyl carbene while two dialkyl/diaryl phosphide ligands serve as bridges between the two Pd centers. The catalytic performance of the resulting library of Pt(II) complexes was tested; all of the cationic phosphines accelerated the prototype 6-endo-dig cyclization of 2-ethynyl-1,1'-biphenyl to afford pentahelicene. The best ligand 1 g was used in the synthesis of two natural products, chrysotoxene and epimedoicarisoside A.

Synthesis, structure and reactivity of cyclopropenyl-1-ylidene stabilized S(II), Se(II) and Te(II) mono- and dications.

The syntheses and structural characterization of carbene-stabilized chalcogen centred mono- and dications employing a reverse electron demand onio-substitutent transfer strategy are reported. The electronic structures of these compounds were determined by density functional calculations and their reactivity towards Pd(0) centres was evaluated.

7-Methylguanine: protonation, formation of linkage isomers with trans-(NH3)2Pt(II), and base pairing properties.

Three protonated forms of 7-methylguanine (7-MeGH, 1) with different counter ions, [7-MeGH(2)]X (X = NO(3), 1a; ClO(4), 1b; BF(4), 1c) and two Pt(II) complexes, trans-[Pt(NH(3))(2)(7-MeGH-N9)(2)](ClO(4))(2) (4) and trans-[Pt(NH(3))(2)(7-MeGH-N9)(7-MeGH-N3)](ClO(4))(2)·3H(2)O (5) are described and their X-ray crystal structures are reported. 1a-1c form infinite ribbons via pairs of intermolecular hydrogen bonds between N1H···O6 and N3···N2H(2) sites, with anions connecting individual ribbons, thereby generating extended sheets. 4 and 5 do not display unusual features, except that 5 represents a rare case of a bis(nucleobase) complex of Pt(II) in which linkage isomers occur. Unlike in a previously reported compound, [Pt(dien)(7-MeGH-N9)](NO(3))(ClO(4)), the Pt coordination planes and the 7-MeGH planes are not coplanar in 4 and 5. The hydrogen bonding behaviour of 7-MeGH, free and when platinated at N9 (complex 4), was studied in Me(2)SO-d(6). It revealed the following: (i) there is no detectable self-association of 1 in Me(2)SO solution. (ii) 1 and 1-methylcytosine (1-MeC) form Watson-Crick pairs. (iii) 4 does not self-associate. (iv) 4 associates with 1-MeC in the Watson-Crick fashion. (v) 4 and 1 interact in solution, but no model can be proposed at present. (vi) Remarkable interaction shifts between 4 and 1 occur when NH(3) is liberated from trans-(NH(3))(2)Pt(II) to give NH(4)(+) in Me(2)SO-d(6). Feasible models, which imply the presence of deprotonated 7-MeG(-) species are proposed. Finally, DFT calculations were carried out to qualitatively estimate the effect of 7-MeGH acidity in [Pt(dien)(7-MeGH-N9)](2+) in dependence of the dihedral angle between the Pt coordination plane and the nucleobase.

Outcomes in different residential settings for people with intellectual disability: a systematic review.

Large-scale reviews of research in deinstitutionalization and community living were last conducted about 10 years ago. Here we surveyed research from 1997 to 2007. Articles were included if the researchers based the study on original research, provided information on the participants and methodology, compared residential arrangements for adults with intellectual disability, and were published in English-language peer-reviewed journals. Sixty-eight articles were found. In 7 of 10 domains, the majority of studies show that community-based services are superior to congregate arrangements. These studies provide more evidence of the benefits of deinstitutionalization and community living and continue to indicate variability in results, suggesting that factors other than the basic model of care are important in determining outcomes.

Deinstitutionalization in intellectual disabilities.

PURPOSE OF REVIEW: The process of deinstitutionalization for intellectual disability services is at different stages across the world, varying from complete closure in Sweden to a vague hope in Taiwan. This review explores recent literature on deinstitutionalization and intellectual disabilities and focuses on papers published in academic journals mainly during 2006. RECENT FINDINGS: Work on deinstitutionalization continues to show that outcomes are better in the community than in institutional care but recent papers highlight that there is more to deinstitutionalization than just hospital closure. Just moving people out of institutions into community settings does not bring about automatic improvement in quality of life in terms of choice and inclusion as well as self-identity and access to effective healthcare and treatment. This is especially true for people with more severe intellectual disabilities as well as complex needs such as challenging behaviour. Some of the current research illustrates that even offenders with intellectual disability can be successfully supported in the community. SUMMARY: Recent research provides further examples and lessons on how community care can and should work, which it would be hoped will help those countries just starting the process of institutional closure to move more quickly to full deinstitutionalization.