Binding of a Co(III) Metalloporphyrin to Amines in Water: Influence of the p and Aromaticity of the Ligand, and pH-Modulated Allosteric Effect.

Metalloporphyrins have been widely utilized as building blocks for molecular self-assembly in organic solvents, but their application in water is less common due to competition from water molecules for the metal center. However, Co(III) metalloporphyrins are notable for their strong binding to two aromatic amine ligands in aqueous buffers. In this study, we present a comprehensive investigation of the binding behavior of Co(III) tetraphenyl sulfonic acid porphyrin with selected aromatic and aliphatic amines in aqueous solution.

Diverse Cyclization Pathways Between Nitriles with Active -Methylene Group and Ambiphilic 2-Pyridylselenyl Reagents Enabled by Reversible Covalent Bonding.

Herein, we describe a novel coupling between ambiphilic 2-pyridylselenyl reagents and nitriles featuring an active α-methylene group. Depending on the solvent employed, this reaction can yield two distinct types of cationic pyridinium-fused selenium-containing heterocycles, 1,3-selenazolium or 1,2,4-selenadiazolium salts, in high yields. This is in contrast to what we observed before for other nitriles.

Left atrial spatial entropy: a novel tool for electrophysiological substrate characterization in atrial fibrillation.

Background: Electrical remodeling has been linked to the progression and recurrence of atrial fibrillation (AF) after catheter ablation (CA). Substrate mapping based solely on a voltage amplitude electrogram (EGM) does not provide a comprehensive understanding of the left atrial (LA) disease. The aim of this study is to assess left atrial spatial entropy (LASE) from voltage maps routinely obtained during AF ablation to further characterize the LA substrate.

Nucleophilicity of the Nitrile N Atom Whose Lone Pair Is Blocked by Metal Coordination. The π-Hole Interaction between an Arene Carbon and the Metal-Bound Nitrile Nitrogen.

Cocrystallization of CuI with NCNMe in the presence of substituted perfluoroarenes─iodoperfluorobenzene (IFB), 4,4'-diiodoperfluorobiphenyl (4,4'-FIBP), and 4-bromoperfluorobenzonitrile (4-BrFBN)─led to the formation of three types of adducts ·2(IFB), ·4,4'FIBP, and ·4-BrFBN ( is CuI(NCNMe)), all studied by X-ray crystallography. In these cocrystals, the coordinated nitrile N atom (whose electron pair is engaged in metal coordination) still acts as an electron donor, forming π-hole interactions, specifically, π-hole···N, with the perfluoroarenes. These interactions were examined in the context of their occurrence alongside other interactions involving C atoms of the electron-deficient aromatic rings and nucleophilic atoms of the copper cluster.

Zwitterionic 2-Phosphaethene-thiolates [(L)P=CS(L)] as PCS Building Blocks (L=NHC, L=PR).

The zwitterionic compounds [(L)P=CS(L)] (3, L=NHC, L=PR), featuring cationic substituents at the phosphorus and carbon atoms, are synthesized as their triflate salts at a multi-gram scale from the reaction of Lewis base adducts of CS, namely L-CS (4), with a combination of [(LP)][OTf] (1[OTf]) and PhP. The feasibility of using 3 as PCS building blocks is showcased in their reactions with representative electrophiles (MeOTf) and nucleophiles (MesMgBr, PhPCH), leading to selective functionalization of the PCS core at the S- and P-terminus, respectively. Additionally, it is reported that 3 can function as ambident nucleophiles with AgOTf (2 equivalents), affording unprecedented linear coordination polymer [Ag(OTf)-μ:κP,κS-((L)P=CS(PCy))] (6 b), where the PCS moiety acts as a bridging ligand in transition metal complexes for the first time.

Noncoordinating Anions as Key Modulators of Supramolecular Structures, Optical and Electrical Properties in Nickel(II) Complexes.

This study explores the synthesis, structural characterization, and examination of two nickel(II) complexes, [Ni( )](NO) (complex ) and [Ni( )](ClO) (complex ), using the newly synthesized organic heterocyclic chelating ligand [4-imidazole-2,6-di(pyrazinyl)pyridine]. Through single-crystal X-ray diffraction, we have detailed the crystal structures of these complexes, highlighting their distorted octahedral geometries and diverse supramolecular interactions including π···π stacking, anion···π, and hydrogen bonding. These interactions crucially influence the formation of distinct one- and two-dimensional supramolecular architectures.

Crystallographic Evidence for Bi(I) as the Heaviest Halogen Bond Acceptor.

Complexation of the green bismuthinidene (RBi) with two equivalents of a highly fluorinated aryl iodide at low temperature allows the crystallographic identification of an unstable red species that can be regarded as an intermediate in an overall Bi(I) → Bi(III) oxidation process. Both C-I bonds are orientated toward the filled 6p orbital of bismuth (Bi-I distances 3.44-3.

Reaction contest: hydrolysis intramolecular cyclisation reaction in alkyl squaramate esters.

The stability and hydrolytic behavior of squaramate esters in aqueous solutions have been investigated. The structure of squaramates and the nature of adjacent groups significantly influence their aqueous stability and reactivity towards nucleophiles. Squaramate esters, lacking or containing weakly basic neighboring group participation (NGP) substitutions, remain stable up to pH 9.

Synthesis, Structural Characterization, and Theoretical Analysis of Nonconventional Bonding in Dinuclear Zinc(II) Complexes with Tridentate Schiff Bases.

Two tridentate N,N,O-donor ligands, HL = 4-chloro-2-(((2-(methylamino)ethyl)amino)methyl)phenol and HL = 4-chloro-2-(((2-(dimethylamino)ethyl)amino)methyl)phenol, have been used to synthesize phenolate-bridged dinuclear complexes [Zn(L)Cl] () and [Zn(L)(N)] (). Single-crystal X-ray diffraction analysis confirmed their structures. Both complexes form assemblies in the solid state.

Synthesis, structural characterization, and theoretical analysis of novel zinc(ii) schiff base complexes with halogen and hydrogen bonding interactions.

In this article, we present the synthesis and characterization of three zinc(ii) complexes, [Zn(HL)] (1), [Zn(HL)]·2HO (2) and [Zn(HL)] (3), with three tridentate Schiff base ligands, HL, HL, and HL. The structures of the complexes were confirmed by single-crystal X-ray diffraction analysis. DFT calculations were performed to gain insights into the self-assembly of the complexes in their solid-state structures.

A Nanosized Porous Supramolecular Lead(II)-'-phenyl(pyridin-2-yl)methylene--phenylthiosemicarbazide Aggregate, Obtained Under Electrochemical Conditions.

A novel nanosized porous supramolecular nonanuclear complex [Pb(HL)Cl(ClO)](ClO)·15HO(solvent) (·15HO(solvent)) is reported that was synthesized by electrochemical oxidation of a Pb anode under the ambient conditions in a CHCN:MeOH solution of '-phenyl(pyridin-2-yl)methylene--phenylthiosemicarbazide (), containing [N(CH)]ClO as a current carrier. The supramolecular aggregate of is enforced by a myriad of Pb···S tetrel bonds (TtBs) established with the thiocarbonyl sulfur atoms of adjacent species, which have been also analyzed by DFT calculations via 2D maps of ELF, Laplacian and RDG properties. Moreover, Pb···Cl TtBs with the central Cl anion, and Pb···O TtBs with the three oxygen atoms of the ClO anion, were revealed.

The Functional substrate in patients with atrial fibrillation is predictive of recurrences after catheter ablation.

Background: Enhanced characterization of the atrial electrical substrate may lead to better comprehension of atrial fibrillation (AF) pathophysiology.

Objective: With the use of high-density substrate mapping, we sought to investigate the occurrence of functional electrophysiological phenomena in the left atrium and to assess potential association with arrhythmia recurrences after catheter ablation.

Methods: Sixty-three consecutive patients with AF referred for ablation were enrolled.

Impact of halogen⋯halogen interaction on the mechanical motion of a 3D Pb(II) coordination polymer of elusive topology.

Herein, we report the synthesis of a Pb(II) based three-dimensional coordination polymer (3D CP), [Pb(DCTP)] (1) [HDCTP = 2,5-dichloroterephthalic acid] with an unprecedented topology, which exhibits a photomechanical effect wherein crystals show jumping upon UV irradiation. The Pb(II) CP forms a type II Cl⋯Cl interaction, which weakens further upon UV irradiation to resolve the anisotropic mechanical strain. The work presented here could be a beacon to the nascent field of photoactuating smart materials.

Intramural Hematoma and Acute Pulmonary Embolism Following Pacemaker Implantation: A Case Report.

Bleeding complications after pacemaker implantation pose risks, including infection and prolonged hospital stay. A case involving aortic intramural hematoma (IMH) arising from subclavian vein access during implantation and concomitant acute pulmonary embolism (PE) is presented. In the present case, IMH probably resulted from subclavian artery vasa vasorum trauma during vein puncture and guidewire advancement, leading to IMH and hemothorax.

Key-to-lock halogen bond-based tetragonal pyramidal association of iodonium cations with the lacune rims of beta-octamolybdate.

The structure-directing "key-to-lock" interaction of double σ-(I)-hole donating iodonium cations with the O-flanked pseudo-lacune rims of [β-MoO] gives halogen-bonded iodonium-beta-octamolybate supramolecular associates. In the occurrence of their tetragonal pyramidal motifs, deep and broad σ-(I)-holes of a cation recognize the molybdate backbone, which provides an electronic pool localized around the two lacunae. The halogen-bonded I⋯O linkages in the structures were thoroughly studied computationally and classified as two-center, three-center bifurcated, and unconventional "orthogonal" I⋯O halogen bonds.

Tetrel Bond Affects the Self-Assembly of Acetylcholine and its Analogues and is an Ancillary Interaction in Protein Binding.

The -N(CH) residue is present in acetylcholine (ACh) and in many of its analogues which are used as selective ACh agonist or antagonists for human therapy. The X-ray structures of four ACh derivatives show the presence of short and linear contacts between the C atoms of -N(CH) groups and lone pair possessing atoms. These contacts can be rationalized as tetrel bonds (TtBs) thanks to their geometric features.

N-Confused strapped calix[4]pyrrole: the missing member of calix[4]pyrrole chemistry.

The first example of N-confused strapped calix[4]pyrrole 5 is presented. The structural integrity of 5 and its regular isomer 4 was unambiguously confirmed by single crystal X-ray diffraction analysis. Anion binding studies using H NMR titration carried out in CDCl revealed a small but detectable tendency of 5 to interact with an anion.

Introducing Cationic Selenium-Containing Triazapentadiene Ligand Framework: Synthesis, Coordination Chemistry, and Antifungal Activity.

Positively charged ligands are scarce. Here, we report the synthesis of unprecedented cationic selenium-containing triazapentadiene ligand framework. The reaction between 2-pyridylselenyl reagents and NaN(CN) in a 2:1 ratio produces the sodium complexes featuring the cationic selenium-containing triazapentadiene (SeTAP) ligand.

Shift of the reduction potential of nickel(II) Schiff base complexes in the presence of redox innocent metal ions.

With the objective of gaining insight into the modulation of the reduction potential of the Ni(II/I) couple, we have synthesized two mononuclear nickel(II) complexes, NiL (HL = ,'-bis(3-methoxysalicylidene)-1,2-diamino-2-methylpropane) and NiL (HL = ,'-bis(3-methoxysalicylidene)-1,3-diamino-2,2-dimethylpropane) of two NO donor ligands and recorded their cyclic voltammograms. Both the nickel complexes show reversible reduction processes for the Ni(II/I) couple in acetonitrile solution but the reduction potential of NiL ( = -1.883 V) is 188 mV more positive than that of NiL ( = -2.

A neutral diphosphene radical: synthesis, electronic structure and white phosphorus activation.

(Im)P-P(Dipp)˙ (1˙), a rare example of a neutral, mixed substituted diphosphene radical, has been prepared by reduction of (Im)PP(Dipp)[OTf] (2[OTf]) and (Im)PP(Cl)(Dipp) (3) with cobaltocene (CoCp) (Im = 4,5-dichloro-1,3-bis(1,3-diisopropylphenyl)-imidazol-2-yl, Dipp = 2,6-diisopropylphenyl). Radical compound 1˙ readily activates white phosphorus (P), resulting in the formation of an intriguing octaphosphane butterfly compound P(Im)(Dipp) (4).