Diindolylamine Preparation and Stability Investigations.

The synthesis of diindolylamines via the palladium-catalyzed cross-coupling of aminoindoles and bromoindoles has been investigated, and efficient coupling conditions using BrettPhos, Pd(OAc), KCO, and tBuOH have been identified. The diindolylamines were found to be unstable in ambient conditions. Blocking the reactive 3-position of the bromoindole coupling partner with a -butyl group results in a diindolylamine with improved air stability.

Palliative Care and Rapid Emergency Screening Tool and the Palliative Performance Scale to Predict Survival of Older Adults Admitted to the Hospital From the Emergency Department.

Background: The Palliative Care and Rapid Emergency Screening (P-CaRES) tool has been validated to identify patients in the emergency department (ED) with unmet palliative care needs, but no prognostic data have been published. The Palliative Performance Scale (PPS) has been validated to predict survival based on performance status and separately has been shown to predict survival among adults admitted to the hospital from the ED.

Objective: To concurrently validate the 6-month prognostic utility of P-CaRES with a replication of prior studies that demonstrated the prognostic utility of the PPS among adults admitted to the hospital from the ED.

Discovery and properties of a new indigoid structure type based on dimeric cis-indigos.

Reactions of indigo with quinones in the presence of sodium hydride leads unexpectedly to products containing two indigo subunits; one indigo is featured in a cis configuration and fused via its indole nitrogen atoms to a second indigo at the central C-C bond of the latter. Structural, optical, and redox properties of the new compounds are reported.

Synthesis and redox chemistry of Pd(ii) complexes of a pincer verdazyl ligand.

A series of palladium(ii) complexes containing a redox-active, tridentate verdazyl ligand of general formula (verdazyl)PdL (L = Cl, CHCN) are synthesized. The tetrazine core of tridentate verdazyl ligand 5 is flanked by two pyridyl groups, creating a geometry in which the ancillary ligand L is bound trans to the verdazyl ring in the square planar metal complexes. Pd(ii) complexes were isolated with the verdazyl ligand in either its neutral radical charge state (6: L = CHCN, 12: L = Cl) or its closed-shell monoanionic charge state (10: L = CHCN, 9: L = Cl).

Diastereomerically Differentiated Excited State Behavior in Ruthenium(II) Hexafluoroacetylacetonate Complexes of Diphenyl Thioindigo Diimine.

Mono- and diruthenium hexafluoroacetylacetonate (hfac) complexes of the thioindigo-N,N'-diphenyldiimine chelating ligand 3 have been prepared. The thioindigo diimine ligand binds to ruthenium in a bidentate fashion in the mononuclear compound 2 and serves as a bidentate chelating bridging ligand in the diruthenium complexes 1a and 1b. Compound 2 was isolated as a racemic mixture while the diruthenium complexes were isolated as the meso (ΔΛ) 1a and rac (ΔΔ and ΛΛ) 1b diastereomers.

Synthesis and redox reactions of bis(verdazyl)palladium complexes.

The synthesis and ligand-centered redox chemistry of palladium complexes bearing two potentially bidentate verdazyl ligands is explored. Reaction of 1,5-diisopropyl-3-pyridin-2-yl-6-oxoverdazyl radical 1 with Pd(NCMe)·2BF gives a complex containing two coordinated verdazyl radicals. The structure of this complex consists of one verdazyl bound to Pd in a bidentate mode and the second verdazyl bound in a monodentate fashion through the pyridine substituent; the fourth coordination site is occupied by a solvent molecule (acetonitrile (3) or dimethyl sulfoxide (4)).

A Computational Study of the Protoisomerization of Indigo and Its Imine Derivatives.

The protoisomerization (isomerization induced by protonation) mechanisms of indigo as well as indigo di- and monoimine derivatives were investigated using computational chemistry. Both density functional theory (M06-2X) and wave function theory (GMC-QDPT) methods were used to obtain reliable results. A solvation model (C-PCM with CH2Cl2 solvent) was employed to mimic the actual environment of the isomerization.

Migration and Gene Flow Among Domestic Populations of the Chagas Insect Vector Triatoma dimidiata (Hemiptera: Reduviidae) Detected by Microsatellite Loci.

Triatoma dimidiata (Latreille, 1811) is the most abundant and significant insect vector of the parasite Trypanosoma cruzi in Central America, and particularly in Guatemala. Tr. cruzi is the causative agent of Chagas disease, and successful disease control requires understanding the geographic distribution and degree of migration of vectors such as T.

Protoisomerization of indigo di- and monoimines.

Indigo di- and monoimines can be protonated to form stable salts in which the central C=C bond has isomerized from a trans to cis configuration. Deprotonation of these salts regenerates the neutral trans species. The protonation chemistry of indigo is also explored.

Synthesis and photophysics of thioindigo diimines and related compounds.

We report the synthesis and comprehensive characterization of diamine and diimine derivatives of the fluorescent compound thioindigo. Diamines 1 were obtained by metal-mediated amine condensation reaction with thioindigo. Oxidation of the products of the coupling reaction provided the diimines 2.

Metal coordination, and metal-ligand redox non-innocence, modulates allosteric C-N bond homolysis in an N-benzyl tetrazine.

Remote coordination of a Ru(hfac)2 moiety to a chelating N-benzyl tetrazine lowers the C-N homolytic bond dissociation enthalpy by approximately 20 kJ mol(-1). The significant bond strength perturbation is believed to arise as a consequence of metal-ligand redox non-innocence.

Classical and non-classical redox reactions of Pd(II) complexes containing redox-active ligands.

Reactivity studies of a Pd(II)-verdazyl complex reveal novel ligand-centred reduction processes which trigger pseudo-reductive elimination at Pd. Reaction of the complex with water induces a ligand-centred redox disproportionation. The reduced verdazyl ligands can also be reversibly protonated.

Synthesis and characterization of heterobimetallic (Pd/B) Nindigo complexes and comparisons to their homobimetallic (Pd2, B2) analogues.

Reactions of Nindigo-BF2 complexes with Pd(hfac)2 produced mixed complexes with Nindigo binding to both a BF2 and a Pd(hfac) unit. These complexes are the first in which the Nindigo ligand binds two different substrates, and provide a conceptual link between previously reported bis(BF2) and bis(Pd(hfac)) complexes. The new Pd/B complexes have intense near IR absorption near 820 nm, and they undergo multiple reversible oxidations and reductions as probed by cyclic voltammetry experiments.

The first "Kuhn verdazyl" ligand and comparative studies of its PdCl2 complex with analogous 6-oxoverdazyl ligands.

The synthesis and characterization of two new N,N'-diarylverdazyl radical ligands and their corresponding PdCl2 complexes are described. One of the two radicals is of the "Kuhn verdazyl" structure type and was made by adaptation of standard synthetic procedures for this class of verdazyl. The N,N'-diphenyl-6-oxoverdazyl was prepared by hydrolysis of a related tetrazane; the resulting N,N'-diphenylcarbohydrazide was condensed with pyridinecarboxaldehyde and then oxidized to the verdazyl according to standard protocols.

Binuclear ruthenium complexes of a neutral radical bridging ligand. A new "spin" on mixed valency.

The electronic structures of (LX)2Ru(Vd)Ru(LX)2 complexes (Vd = 1,5-diisopropyl-3-(4,6-dimethyl-2-pyrimidinyl)-6-oxoverdazyl radical; LX = acac (acetylacetonate) or hfac (hexafluoroacetylacetonate)) in multiple charge states have been investigated experimentally and computationally. The main focus was to probe the consequences of the interplay between the ruthenium ions and the redox-active verdazyl ligand for possible mixed-valent behavior. Cyclic voltammetry studies reveal one reversible reduction and one reversible oxidation process for both complexes; in addition the acac-based derivative possesses a second reversible oxidation.

Water-soluble, luminescent iridium(III)-ytterbium(III) complexes using dipyrido[3,2-a:2',3'-c]phenazine derivatives as bridging units.

Amino-substituted dipyrido[3,2-a:2',3'-c]phenazine (L(1)) and dimethyl-dipyrido[3,2-a:2',3'-c]phenazine (L(2)) have been investigated as: (i) chromophores in cyclen-based ligands for lanthanide(III) ions; (II) ancillary co-ligands in cyclometalated iridium(III) complexes; (III) bridging, linker units in covalently linked, water-soluble bimetallic lanthanide(III) iridium(III) hybrid complexes. The dipyrido[3,2-a:2',3'-c]phenazine (dppz) derivatives can act as sensitising chromophores (λ(ex) 400 nm) for Yb(III), resulting in characteristic near-IR emission at 950-1050 nm. The incorporation of dppz-type ligands into cyclometalated Ir(III) complexes of the general type [Ir(epqc)(2)(L(n))](PF(6)) (where epqc = ethylphenylquinoline carboxylate) gave luminescent species with solvent-sensitive emission properties.

Electronic structure investigations of neutral and charged ruthenium bis(β-diketonate) complexes of redox-active verdazyl radicals.

The electronic structures of (Vd)Ru(LX)(2) complexes (Vd = 1,5-diisopropyl-3-(2-pyridyl)-6-oxoverdazyl radical; LX = acac or hfac) as neutral, cationic, and anionic species have been investigated experimentally and computationally to probe the interplay between the ruthenium ion and the redox-active verdazyl ligand. The cationic complexes were prepared by oxidation of the corresponding neutral species with silver(I) salts. The hfac-based anionic complex was synthesized by reduction of the neutral species with cobaltocene, but the anionic acac analogue could not be prepared.

Redox-active bridging ligands based on indigo diimine ("Nindigo") derivatives.

Reactions of indigo with a variety of substituted anilines produce the corresponding indigo diimines ("Nindigos") in good yields. Nindigo coordination complexes are subsequently prepared by reactions of the Nindigo ligands with Pd(hfac)(2). In most cases, binuclear complexes are obtained in which the deprotonated Nindigo bridges two Pd(hfac) moieties in the expected bis-bidentate binding mode.

Treatments for autism: parental choices and perceptions of change.

Empirically conducted studies of the efficacy of various treatments for autism are limited, which leaves parents with little evidence on which to base their treatment decisions (Kasari, Journal of Autism and Developmental Disorders, 32: 447-461, 2002). The purpose of this study was to examine the types of treatments in current use by families of children with ASD. In addition, parents' perceptions of improvement in their child's functioning were explored.

"Nindigo": synthesis, coordination chemistry, and properties of indigo diimines as a new class of functional bridging ligands.

Reactions of indigo with anilines provide a simple route to indigo N,N'-diaryldiimines ("Nindigo"), a new binucleating ligand with two beta-diketiminate-type metal binding sites. Bis-palladium complexes have interesting ligand-centred properties such as redox activity and intense near infrared absorption.

Verdazyl radicals as redox-active, non-innocent, ligands: contrasting electronic structures as a function of electron-poor and electron-rich ruthenium bis(beta-diketonate) co-ligands.

Spectroscopic, structural, and computational studies of verdazyl radical-ruthenium complexes reveal the verdazyl to be a redox-active and non-innocent ligand. The ensuing delocalization of charge is highly sensitive to the nature of the beta-diketonate co-ligands.

Effects of electron-deficient beta-diketiminate and formazan supporting ligands on copper(I)-mediated dioxygen activation.

Copper(I) complexes of a diketiminate featuring CF(3) groups on the backbone and dimethylphenyl substituents (4) and a nitroformazan (5) were synthesized and shown by spectroscopy, X-ray crystallography, cyclic voltammetry, and theory to contain copper(I) sites electron-deficient relative to those supported by previously studied diketiminate complexes comprising alkyl or aryl backbone substituents. Despite their electron-poor nature, oxygenation of LCu(CH(3)CN) (L = 4 or 5) at room temperature yielded bis(hydroxo)dicopper(II) compounds and at -80 degrees C yielded bis(mu-oxo)dicopper complexes that were identified on the basis of UV-vis and resonance Raman spectroscopy, spectrophotometric titration results (2:1 Cu/O(2) ratio), electron paramagnetic resonance spectroscopy (silent), and density functional theory calculations. The bis(mu-oxo)dicopper complex supported by 5 exhibited unusual spectroscopic properties and decayed via a novel intermediate proposed to be a metallaverdazyl radical complex, findings that highlight the potential for the formazan ligand to exhibit "noninnocent" behavior.

Synthesis and characterization of 3-cyano- and 3-nitroformazans, nitrogen-rich analogues of beta-diketimine ligands.

The synthesis and characterization of several formazans containing strong electron-withdrawing substituents (cyano and nitro) in the 3 position of the ligand backbone are described. Reactions of aryldiazonium cations with the conjugated bases of either cyanoacetic acid or nitromethane lead to 1,5-diaryl-3-cyano- or 3-nitroformazans, respectively. When these reactions are carried out in aqueous conditions, the range of aromatic groups is limited by the stability of the diazonium salt.