Exploring unsymmetrical diboranes(4) as boryl ligand precursors: platinum(ii) bis-boryl complexes

A series of five unsymmetrical platinum(II) bis-boryl complexes, bearing two distinct boryl ligands, are obtained by the oxidative addition reaction of unsymmetrical diborane(4) derivatives, bearing either two different dialkoxy or one dialkoxy and one diamino boryl moiety, with [(Ph3P)2Pt(C2H4)]. All five complexes were structurally and spectroscopically characterised. The bis-boryl platinum(II) complexes exhibit slightly distorted square-planar cis-boryl structures with acute B–Pt–B angles, short B/B distances of 2.44–2.55 °A and relatively long trans-boryl P–Pt distances around 2.34 °A. The 31P–195Pt NMR coupling constants are indicative for the strongly donating/trans-influencing boryl ligands. Despite the structural and spectroscopic data at hand no finally conclusive order of the donor properties/transinfluence of the boryl ligands can be deduced on the basis of these data. This may be explained by an (residual) interaction of two boryl ligands

Functional brain networks in the schizophrenia spectrum and bipolar disorder with psychosis

Psychotic experiences have been proposed to lie on a spectrum, ranging from subclinical experiences to treatment-resistant schizophrenia. We aimed to characterize functional connectivity and brain network characteristics in relation to the schizophrenia spectrum and bipolar disorder with psychosis to disentangle neural correlates to psychosis. Additionally, we studied antipsychotic medication and lithium effects on network characteristics. We analyzed functional connectivity strength and network topology in 487 resting-state functional MRI scans of individuals with schizophrenia spectrum disorder (SCZ), bipolar disorder with a history of psychotic experiences (BD), treatment-naïve subclinical psychosis (SCP), and healthy controls (HC). Since differences in connectivity strength may confound group comparisons of brain network topology, we analyzed characteristics of the minimum spanning tree (MST), a relatively unbiased backbone of the network. SCZ and SCP subjects had a lower connectivity strength than BD and HC individuals but showed no differences in network topology. In contrast, BD patients showed a less integrated network topology but no disturbances in connectivity strength. No differences in outcome measures were found between SCP and SCZ, or between BD patients that used antipsychotic medication or lithium and those that did not. We conclude that functional networks in patients prone to psychosis have different signatures for chronic SCZ patients and SCP compared to euthymic BD patients, with a limited role for medication. Connectivity strength effects may have confounded previous studies, as no functional network alterations were found in SCZ after strict correction for connectivity strength.</p

Elusive Phosphine Copper(I) Boryl Complexes: Synthesis, Structures, and Reactivity

We report the first isolation of phosphine copper boryl complexesspecies pivotal to numerous copper-catalyzed borylation reactions. The reaction of diboron(4) derivatives with copper <i>tert</i>-butoxide complexes of phosphine ligands allows the isolation of the dimeric μ-boryl-bridged Cu­(I) complexes [(<i>i</i>Pr₃P)­Cu–Bdmab]₂ (<b>4</b>) and [(C₆H₄(Ph₂P)₂)­Cu–Bpin]₂ (<b>6</b>) with Cu···Cu distances of 2.24–2.27 Å (dmab = (NMe)₂C₆H₄, pin = (OCMe₂)₂)). A slightly more sterically demanding boryl ligand furnishes the unprecedented multinuclear copper boryl complex [(<i>i</i>Pr₃P)₂Cu₈(B­(<i>i</i>PrEn))₃(O<i>t</i>Bu)₃] (<b>5</b>), a potential intermediate of the decomposition of an initial Cu­(I) boryl complex (<i>i</i>PrEn = (N<i>i</i>Pr)₂C₂H₄). All complexes were characterized by single-crystal X-ray diffraction, NMR spectroscopy, and elemental analysis. DFT computations support the nature of these unique complexes and give insight into their electronic structures

Hydrogen-Bridged Digermyl and Germylsilyl Cations

The synthesis of the digermyl and germylsilyl hydronium borates <b>7</b>[B­(C₆F₅)₄] and <b>8</b>[B­(C₆F₅)₄] is reported. Spectroscopic (IR, NMR) and structural data supported by the results of density functional calculations indicate in both cases a symmetric or almost symmetric E–H–E′ three-center–two-electron linkage (<b>7</b>, E = E′ = Ge; <b>8</b>, E = Si, E′ = Ge). The [B­(C₆F₅)₄]⁻ and the [HCB₁₁H₅Br₆]⁻ salts of both cations are active in catalytic hydrodefluorination reactions of alkyl and benzyl fluorides. No significant effect of the element atom E on the determined turnover numbers was found