Mononuclear Rare-Earth Metalloligands Exploiting a Divergent Ligand.

Rare-earth tris-diketonato [RE(dike)pyterpy] metalloligands can be prepared reacting at room temperature [RE(dike)dme] (dme = 1,2-dimethoxyethane; dike = tta with Htta = 2-thenoyltrifluoroacetone and RE = La, ; Y, ; Eu, ; Dy, ; or dike = hfac with Hhfac hexafluoroacetylacetone, and RE = Eu, ; Tb, ; Yb ) with 4'-(4‴-pyridil)-2,2':6',2″-terpyridine (pyterpy). The molecular structures of , , , and have been studied through single-crystal X-ray diffraction showing mononuclear neutral complexes with the rare-earth ion in coordination number nine and with a muffin-like coordination geometry. [RE(tta)pyterpy] promptly reacts with [M(tta)dme] with formation of [Mpyterpy][RE(tta)] (M = Zn, RE = Y, ; M = Co, RE = Dy, ).

Size Selectivity in Heterolanthanide Molecular Complexes with a Ditopic Ligand.

The similar reactivity of lanthanides generally leads to statistically populated polynuclear complexes, making the rational design of ordered hetero-lanthanide compounds extremely challenging. Here we report on the site selectivity in hetero-lanthanide tetranuclear complexes afforded by the relatively simple ditopic pyterpyNO ligand (4'-(4-pyridil)-2,2':6',2"-terpyridine N-oxide). The sequential room temperature reaction of RE (tta) (pyterpyNO) (where RE=Y, (1); Eu, (2), Dy, (3) Htta=2-thenoyltrifluoroacetone) with La(tta) dme (dme=dimethoxyethane) yielded Y La (tta) (pyterpyNO) (4), Dy La (tta) (pyterpyNO) (5) and Eu La (tta) (pyterpyNO) (6).

Stoichiometrically Controlled Assembly of Lanthanide Molecular Complexes of the Heteroditopic Divergent Ligand 4'-(4-Pyridyl)-2,2':6',2″-terpyridine -Oxide in Hypodentate or Bridging Coordination Modes. Structural, Magnetic, and Photoluminescence Studies.

Mononuclear rare-earth tris-β-diketonato complexes RE(tta)dme [RE = Y (), La (), Dy (), or Eu (); Htta = 2-thenoylacetone; dme = 1,2-dimethoxyethane] react cleanly at room temperature in a 1:1 molar ratio with the heteroditopic divergent ligand 4'-(4-pyridyl)-2,2':6',2″-terpyridine -oxide (pyterpyNO) to yield RE(tta)(pyterpyNO), where = 2 for RE = Y (), Dy (), or Eu () and = 3 for RE = La (). The crystal structure of revealed a dinuclear compound with two pyterpyNO's bridging through the oxygen atom in a hypodentate mode leaving the terpyridine moieties uncoordinated. Using a metal:pyterpyNO molar ratio of 2 for RE = Y (), Dy (), or Eu (), it was possible to isolate the molecular complexes RE(tta)(pyterpyNO), while using a 5:3 molar ratio, the product La(tta)(pyterpyNO) () can be obtained.

Analysis of the cost-effectiveness of surfactant treatment (Curosurf®) in respiratory distress syndrome therapy in preterm infants: early treatment compared to late treatment.

Background: The best criteria for surfactant treatment in the perinatal period are unknown and this makes it of interest to consider the possible economic implications of lessening the use of more restrictive criteria.

Objective: The objective of this study is the evaluation of the costs of respiratory care for preterm infants with Respiratory Distress Syndrome (RDS) treated with "early rescue" surfactant compared to a "late rescue" strategy.

Methods: The study was carried out applying the costs of materials used, of staff and pharmacological therapy calculated in the Neonatal Intensive Care Unit (NICU) of an Italian hospital to the Verder et al.