Electronic Configurations and the Effect of Peripheral Substituents of (Nitrosyl)iron Corroles.

There have been debates on the electronic configurations of (nitrosyl)iron corroles for decades. In this work, pentacoordinate [Fe(TPC)(NO)], [Fe(TTC)(NO)], and [Fe(TFC)(NO)] with different -substituted phenyl groups (TPC, TTC, and TFC = tris(phenyl, 4-tolyl, or 4-fluorophenyl)corrole, respectively) have been isolated and investigated by various techniques including single-crystal X-ray diffraction, UV-vis spectroscopy, cyclic voltammetry, Fourier transform infrared, NMR, and absorption fine structure spectroscopy. Multitemperature and high-magnetic-field (3, 6, and 9 T) Mössbauer spectroscopy was also applied on all three complexes, which determined the = 0 diamagnetic states, consistent with the magnetic susceptibility and electron paramagnetic resonance measurements.

Perspectives on Ligand Properties of N-Heterocyclic Carbenes in Iron Porphyrin Complexes.

There has been considerable research interest in the ligand nature of N-heterocyclic carbenes (NHCs). In this work, two six-coordinate NHC iron porphyrin complexes [Fe(TTP)(1,3-MeImd)] (TTP = tetratolylporphyrin, 1,3-MeImd = 1,3-dimethylimidazol-2-ylidene) and [Fe(TDCPP)(1,3-MeImd)]ClO (TDCPP = 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin) are reported. Single-crystal X-ray characterizations demonstrate that both complexes have strongly ruffled conformations and relatively perpendicular ligand orientations which are forced by the sterically bulky 1,3-MeImd NHC ligands.

Effects of Superparamagnetic Iron Nanoparticles on Electrocatalysts for the Reduction of Oxygen.

It is of great research interest to understand the nanostructures contributing to the activity observed in the reduction of oxygen by non-platinum group metal (PGM) electrocatalysts in acidic media. Iron- and nitrogen-containing carbon networks are often the most studied structures, among which single-atom iron-coordinated nitrogen (FeN) moieties have often been proposed to be the structures leading to the high activity in these non-PGM electrocatalysts. Iron nanoparticles embedded within a carbon support are also formed under certain conditions as a result of the synthetic processes in making non-PGM electrocatalysts.

Preparation of Nonprecious Metal Electrocatalysts for the Reduction of Oxygen Using a Low-Temperature Sacrificial Metal.

Non-platinum group metal (non-PGM) electrocatalysts for the oxygen reduction reaction (ORR) are generally composed of iron, nitrogen, and carbon synthesized through high-temperature pyrolysis. Among the various types of precursors, metal-organic frameworks (MOFs), zeolitic imidazolate framework (ZIF)-8 in particular, have often been used in the synthesis. The pyrolysis of ZIF-8 precursor relies on the use of Zn as a sacrificial metal (SM), and the optimal processing temperatures often exceed 1000 °C to generate active non-PGM catalysts.

Intermolecular Interactions and Intramolecular Couplings of Binuclear Porphyrin Models for Cytochrome Oxidase.

Cytochrome oxidase (CO) has a binuclear active site composed of a high-spin heme group and a tris-histidine-ligated copper ion (Cu). By using two different porphyrin models derived by Gunter (HTPyPP) and us (HTImPP), we have isolated several mono- and binuclear complexes including one carbonyl and three chloride derivatives which are determined by 100 K single-crystal X-ray. Low-temperature (4 K) EPR and multitemperature (295-25 K) Mössbauer investigations on the products not only confirmed the spin states of the two metal ions ( = 5/2 Fe and = 1/2 Cu) but also revealed the intermolecular interactions and intramolecular couplings which are in accordance with the crystal structural features.

New Insights into the Ligand Nature of Carbene: Synthesis and Characterizations of Six-Coordinate Iron(II) Carbene Porphyrin Complexes.

Several six-coordinate iron(II) carbene tetra(pentafluorophenyl)porphyrin (TFPP) complexes, [Fe(TFPP)(CPh)(1-EtIm)] (1-EtIm = 1-ethylimidazole) and [Fe(TFPP)(CPh)(1,2-MeIm)] (1,2-MeIm = 1,2-dimethylimidazole), are isolated and studied by UV-vis, single-crystal X-ray, and Mössbauer spectroscopies. The single-crystal structural studies revealed noteworthy features including strong and "hard" axial carbene bonds (Fe-C) but "flexible" trans ligand bonds (Fe-N). The Mössbauer spectra of [Fe(TFPP)(CPh)(1-EtIm)] and [Fe(TFPP)(CPh)(1,2-MeIm)] are obtained on solid-state samples between 25 and 295 K, which give very large Δ E values (1.

Hydrogen-Bonding Effects in Five-Coordinate High-Spin Imidazole-Ligated Iron(II) Porphyrinates.

The influence of hydrogen binding to the N-H group of coordinated imidazole in high-spin iron(II) porphyrinates has been studied. The preparation and characterization of new complexes based on [Fe(TPP)(2-MeHIm)] (TPP is the dianion of tetraphenylporphyrin) are reported. The hydrogen bond acceptors are ethanol, tetramethylene sulfoxide, and 2-methylimidazole.

The Genetics of Endophenotypes of Neurofunction to Understand Schizophrenia (GENUS) consortium: A collaborative cognitive and neuroimaging genetics project.

Background: Schizophrenia has a large genetic component, and the pathways from genes to illness manifestation are beginning to be identified. The Genetics of Endophenotypes of Neurofunction to Understand Schizophrenia (GENUS) Consortium aims to clarify the role of genetic variation in brain abnormalities underlying schizophrenia. This article describes the GENUS Consortium sample collection.

Iron(II) Bis(imidazole) Derivatives of a Binuclear Porphyrin Model: Crystal Structures and Mössbauer Properties.

A new sterically hindered "picket fence-like" porphyrin with chelates for the second metal atom, HTImPP (TImPP = meso-tetrakis[α,α,α,α-o-(5-imidazolecarboxylaminophenyl)]porphyrinato), is developed and used in the synthesis of four iron(II) bis(imidazole) derivatives, which are characterized by single crystal X-ray and other spectroscopies. The comprehensive studies on the crystal structures revealed noteworthy features including new axial ligand arrangements, deformed porphyrin planes, and strongly tilted pickets which can be rationalized by analysis of the intra- and intermolecular interactions. Solid-state Mössbauer experiments on [Fe(TImPP)(1-MeIm)] were conducted at several temperatures from 295 to 25 K.

Assessment of Proteomic Measures Across Serious Psychiatric Illness.

The diagnoses of serious psychiatric illnesses, such as schizophrenia, schizoaffective disorder, and bipolar disorder, rely on the subjective recall and interpretation of often overlapping symptoms, and are not based on the objective pathophysiology of the illnesses. The subjectivity of symptom reporting and interpretation contributes to the delay of accurate diagnoses and limits effective treatment of these illnesses. Proteomics, the study of the types and quantities of proteins an organism produces, may offer an objective biological approach to psychiatric diagnosis.

Cross-Tissue Exploration of Genetic and Epigenetic Effects on Brain Gray Matter in Schizophrenia.

Closely linking genetics and environment factors, epigenetics has been of increasing interest in psychiatric disease studies. In this work, we integrated single nucleotide polymorphisms (SNPs), DNA methylation of blood and saliva, and brain gray matter (GM) measures to explore the role of genetic and epigenetic variation to the brain structure changes in schizophrenia (SZ). By focusing on the reported SZ genetic risk regions, we applied a multi-stage multivariate analysis to a discovery dataset (92 SZ patients and 110 controls, blood) and an independent replication dataset (93 SZ patients and 99 controls, saliva).

Electronic Configuration and Ligand Nature of Five-Coordinate Iron Porphyrin Carbene Complexes: An Experimental Study.

The five-coordinate iron porphyrin carbene complexes [Fe(TPP) (CCl)] (TPP = tetraphenylporphyrin), [Fe(TTP) (CCl)] (TTP = tetratolylporphyrin) and [Fe(TFPP) (CPh)] (TFPP = tetra(pentafluorophenyl)porphyrin), utilizing two types of carbene ligands (CCl and CPh), have been investigated by single crystal X-ray, XANES (X-ray absorption near edge spectroscopy), Mössbauer, NMR and UV-vis spectroscopies. The XANES suggested the iron(II) oxidation state of the complexes. The multitemperature and high magnetic field Mössbauer experiments, which show very large quadrupole splittings (QS, ΔE), determined the S = 0 electronic configuration.

Unique Axial Imidazole Geometries of Fully Halogenated Iron(II) Porphyrin Complexes: Crystal Structures and Mössbauer Spectroscopic Studies.

The synthesis and characterization of several electron-poor iron(II) porphyrin (FeTFPPBr) complexes with axial imidazole ligands are reported. The single-crystal X-ray structures have been studied by a combination of crystal packing and Hirshfeld surface calculations, which explained the unusual axial-ligand geometries, e.g.

Identification of carbon-encapsulated iron nanoparticles as active species in non-precious metal oxygen reduction catalysts.

The widespread use of fuel cells is currently limited by the lack of efficient and cost-effective catalysts for the oxygen reduction reaction. Iron-based non-precious metal catalysts exhibit promising activity and stability, as an alternative to state-of-the-art platinum catalysts. However, the identity of the active species in non-precious metal catalysts remains elusive, impeding the development of new catalysts.

Joint sparse canonical correlation analysis for detecting differential imaging genetics modules.

Motivation: Imaging genetics combines brain imaging and genetic information to identify the relationships between genetic variants and brain activities. When the data samples belong to different classes (e.g.

Network analysis of functional brain connectivity in borderline personality disorder using resting-state fMRI.

Borderline personality disorder (BPD) is associated with symptoms such as affect dysregulation, impaired sense of self, and self-harm behaviors. Neuroimaging research on BPD has revealed structural and functional abnormalities in specific brain regions and connections. However, little is known about the topological organizations of brain networks in BPD.

Behavioral and emerging pharmacologic treatment options for cognitive impairment in schizophrenia.

In recent years, the goal of treatment for individuals with schizophrenia has shifted from symptom control to functional recovery. For recovery to occur, the substantial cognitive impairments associated with this disorder must be addressed. Advances in neuroscience have paved the way for the development of more effective behavioral and pharmacologic treatments.

Assessing cognitive impairment in patients with schizophrenia.

Schizophrenia has existed as a distinct disorder for nearly a century, and, ever since this disorder was first described and studied, cognitive impairment has been recognized as a prominent feature. However, the positive symptoms of schizophrenia moved to the forefront of clinical and research attention in the latter half of the twentieth century. With the new movement toward functional recovery in schizophrenia, cognitive dysfunction has become an important treatment target.

Graph Metrics of Structural Brain Networks in Individuals with Schizophrenia and Healthy Controls: Group Differences, Relationships with Intelligence, and Genetics.

Objectives: One of the most prominent features of schizophrenia is relatively lower general cognitive ability (GCA). An emerging approach to understanding the roots of variation in GCA relies on network properties of the brain. In this multi-center study, we determined global characteristics of brain networks using graph theory and related these to GCA in healthy controls and individuals with schizophrenia.

Quetiapine's effect on the SCL-90-R domains in patients with borderline personality disorder.

Background: This study aimed to examine the impact of quetiapine on the symptom and distress domains measured by the Symptom Checklist-90-Revised (SCL-90-R) in patients with borderline personality disorder (BPD).

Methods: Ninety-five participants meeting DSM-IV diagnostic criteria for BPD were randomly assigned to low-dosage (quetiapine, 150 mg/d; n = 33), moderate-dosage (quetiapine, 300 mg/d; n = 33), or placebo (n = 29). SCL-90-R was administered weekly over the course of an 8-week double-blind treatment phase.

All high-spin (S = 2) iron(ii) hemes are NOT alike.

A common structural motif in heme proteins is a five-coordinate species in which the iron is coordinated by a histidyl residue. The widely distributed heme proteins with this motif are essential for the well being of humans and other organisms. We detail the differences in molecular structures and physical properties of high-spin iron(ii) porphyrin derivatives ligated by neutral imidazole, hydrogen bonded imidazole, and imidazolate or other anions.

Brain structure and function correlates of cognitive subtypes in schizophrenia.

Stable neuropsychological deficits may provide a reliable basis for identifying etiological subtypes of schizophrenia. The aim of this study was to identify clusters of individuals with schizophrenia based on dimensions of neuropsychological performance, and to characterize their neural correlates. We acquired neuropsychological data as well as structural and functional magnetic resonance imaging from 129 patients with schizophrenia and 165 healthy controls.