Apical Position Research Articles

Crystal structure and Hirshfeld surface analysis of bis(benzoylacetonato)(ethanol)dioxidouranium(VI)

A new uranium metal–organic complex salt, [U(C10H9O2)2O2(C2H6O)], with benzoyl acetone, namely, bis(benzoylacetonato)(ethanol)dioxidouranium(VI), was synthesized. The compound has monoclinic P21/n symmetry. The geometry of the seven-coordinate U atom is pentagonal bipyramidal, with the uranyl oxygen atoms in apical positions. In the complex, the ligands bind to the metal through oxygen atoms. Additional weak O—H...O contacts between the cations and anions consolidate the three-dimensional arrangement of the structure. On the Hirshfeld surface, the largest contributions come from the short contacts such as van der Waals forces, including H...H, O...H and C...H. Interactions including C...C and O...C contacts were also observed; however, their contribution to the overall cohesion of the crystal structure is minor. A packing analysis was performed to check the strength of the crystal packing.

Enhanced Electrochemical Performance of Copper(II) Metal Organic Framework‐Ternary Quantum Dots Composite towards the Detection of Bisphenol A

AbstractTernary quantum dot metal organic framework (MOFs) composite sensor formulated as (ZnInSe2@[Cu(2‐HNA)2(H2O)]) with an enhanced electrochemical performance was synthesized from a copper(II) metal‐organic framework complex ([Cu(2‐HNA)2(H2O)]) and ZnInSe2 ternary quantum dot (TQDs). The compounds were characterized by Fourier transform infrared spectroscopy, Ultraviolet‐Visible spectroscopy, transmission electron microscopy, scanning electron microscopy, single crystal X‐ray crystallography, and photoluminescence. Molecular structure of the copper(II) complex revealed a distorted square pyramidal geometry with two molecules of 2‐hydroxy‐1‐naphthaldedyde at the basal planes as bidentate chelating ligands with a coordinated water molecule at the apical position. TEM micrographs revealed monodispersed composite with an average particle size of 3.2 nm. The composite and its precursors were used as ectrochemical sensor for the detection of bisphenol A, using cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. The composite modified on a gold electrode exhibited enhanced electrochemical performance in comparison to those of the MOFs and TQDs. The reaction process at the surface of the modified electrode with the composite is diffusion controlled with a limit of detection, and limit of quantitation of 4.70 nM and 14.26 nM over a concentration range of 10–50 nM (S/N=3). The gold modified composite electrode is stable and could serve as a model for the development of electrochemical sensor to determine BPA.

Acyclic Diaminocarbene Platinum(IV) Complexes Synthesized by the Oxidative Addition of MeI and I<sub>2</sub>

The oxidative addition of methyl iodide or molecular iodine to the bis(С,N-chelate) deprotonated diaminocarbene platinum(II) complexes [Pt{C(N(H)Ar)(NC(N(H)Ph)N(Ph)}2] (Ar = C6H3-2,6-Me2 (Xyl), C6H2-2,4,6-Me3 (Mes), and C6H4-4-Me (pTol)) affords the corresponding platinum(IV) derivatives in a yield of 89–99%. The addition of CF3CO2H is accompanied by the protonation of the nitrogen atoms of the diaminocarbene fragment to form the cationic complexes [[PtI(X)-{C(N(H)Ar)(NC(N(H)Ph)N(Ph)}2]CF3CO2H (X = Me, I). The structures of the compounds are determined by elemental analysis; high resolution mass spectrometry with electrospray ionization (ESI HRMS); IR spectroscopy; 1H, 13C{1H}, 19F{1H}, and 195Pt{1H} NMR spectroscopy; 2D NMR spectroscopy (1H,1Н COSY, 1H,1Н NOESY, 1H,13C HSQC, 1H,13C HMBC, 1H,15N HSQC, 1H,15N HMBC), and X-ray diffraction (XRD) and thermogravimetric analyses. The synthesized platinum(IV) complexes are thermally stable to 200–260°C and are electroneutral molecules with the octahedral coordination sphere formed by two deprotonated diaminocarbene C,N-chelate substituents and iodine and methyl or two iodine atoms localized in the apical positions.

Synthesis, Characterization, Crystal structure determination and DFT study of a six coordinated Cu (II) complex of a phosphorous based tris-(2-pyridinylamino) phosphene sulphide ligand and its acid catalysed hydrolysis

One mono nuclear copper(II) complex (Cu-TPPS-OOCCH3 with structural formula C17H19CuN6O3PS) is synthesized using a novel tripodal tetradentate ligand, tris-(2-pyridinylamino)phosphene sulphide (TPPS), which has three pyridinylamino groups attached to a phosphorus atom connected to a sulphur atom (PS). The equatorial positions of the complex are occupied by three amino N-atoms of three aminopyridyl groups and one O-atom of the acetate group. The apical position is occupied by other O-atom of acetate group and one secondary N-atom of the tripodal ligand. The complex has been synthesized and purified as green solid and characterized by various spectroscopic techniques and the structure has been determined by X-ray single crystal diffraction study. The geometry optimizations and calculations of energies of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the compounds are performed by using the hybrid B3LYP density functional theory (DFT) along with the def2TZVP basis set.

Syntheses, characterization and antibacterial activity of mononuclear and dinuclear copper(II) complexes containing a hydrazone ligand

An aroylhydrazone compound (HL) was prepared and explored as a ligand (HL = N’-(2-hydroxy-4-methoxybenzylidene)-3-hydroxy-4-methoxybenzohydrazide). Reaction of the aroylhydrazone ligand with copper bromide and copper chloride afforded two new copper(II) complexes, [Cu2Br2L2] (1) and [CuL(DMF)]Cl (2), respectively. The aroylhydrazone ligand and copper complexes were characterized by CHN elemental analyses and infrared spectroscopy. Structures were further confirmed by single crystal X-ray diffraction experiments. The aroylhydrazone compound coordinates to Cu atoms through its phenolate oxygen, imino nitrogen and carbonyl oxygen. The Cu atom in 1 adopts a square pyramidal coordination, with three donor atoms of one L and one phenolate oxygen of a second L in the basal plane, and with one Br ligand at the apical position. The Cu atom in 2 is square pyramidal, with three donor atoms of one L and one oxygen of a DMF ligand in the basal plane, and with one Cl ligand at the apical position. Crystal structures of the aroylhydrazone and the copper complexes are stabilized by hydrogen bonds. The complexes possess antibacterial activities against B. subtilis, S. aureus and E. coli.

Safety and efficacy of orthodromic snare technique in left ventricular lead delivery in cardiac resynchronization implantation.

Cardiac resynchronization therapy (CRT) improves ventricular function, but a positive response to CRT is often limited due to left ventricular (LV) lead placement in a suboptimal position. Complex coronary venous anatomy can hinder the placement of an LV lead in the target vessel, leading to poor CRT response. To report experience with snare-assisted LV lead delivery in CRT and compare outcomes with the conventional LV lead delivery. This is a single-center retrospective case-control study of CRT implants between 2016 and 2021. Snare-assisted lead delivery was performed in cases where conventional lead placement failed or when a preferred target vessel had anatomy amenable to the technique. Safety and outcomes were compared to conventional LV lead placement cases. Among 180 CRT cases, 33 were snare-assisted, and 147 were conventional LV lead placements. Median follow-up was 924 days in the snare and 618.5 days in the control group. The lead placement was successful in 28/33 snare and 138/147 control cases. A mid-vessel segment was attained in 89.3% of snare and 72.5% of control cases(p=.03). The apical position was more frequently observed in the control group (26.8% vs. 7.1%, p=.03). All-cause mortality trended lower in the snare group (6.1%) compared to (17.1%) in the control group (p=.13). Snare-assisted LV lead delivery is a safe and effective technique that can be utilized for overcoming complex venous anatomy.

Influence of apical finish line location of tooth preparations on the scanning accuracy of intraoral scanners with various focal lengths and scanning technologies

Statement of problemLimited studies have reported the influence of finish line location on the accuracy of intraoral scanners (IOSs). Focal length is a hardware characteristic of IOSs. Whether there is a relationship between scanning accuracy of tooth preparations with the finish located at different apical positions and focal length and IOS technology or system remains uncertain. PurposeThe purpose of the present in vitro study was to assess the influence of the apical finish line location of tooth preparations on the accuracy of 4 IOSs with various focal lengths and scanning technologies. Material and methodsA maxillary typodont with a crown preparation on the left first molar was digitized (T710). Afterwards, a removable die was created on the prepared first molar of the virtual cast and duplicated to create 4 dies with different apical finish line locations: 2- or 1-mm supragingival, 0-mm or equigingival, and −0.5-mm or intracrevicular. The cast and die designs were additively fabricated (Asiga Pro 4K with Keystone Model Ultra). Each die was independently scanned by using the same laboratory scanner (reference scans). Four groups were created: TRIOS 5, i700, iTero, and Primescan. Four subgroups were developed depending on the apical position of the finish line (n=15). In each subgroup, the cast was assembled by positioning the corresponding die into the cast. The cast was then scanned by using the corresponding IOS. The reference scans were used as a control to compute the root mean square (RMS) error discrepancies with each experimental scan on the preparation and margin of the preparation areas. Two-way ANOVA and pairwise comparisons were used to analyze trueness (α=.05). The Levene and pairwise comparisons using the Wilcoxon Rank sum test were used to analyze precision (α=.05). ResultsTrueness discrepancies in the preparation area were found among the groups (P=.010) and subgroups (P<.001), with a significant interaction between group×subgroup (P<.001). The −0.5 mm location obtained significantly worse trueness in the preparation area. The TRIOS 5 and i700 obtained the best trueness in the preparation area. Trueness discrepancies in the margin area were found among the groups (P=.002) and subgroups (P<.001), with a significant interaction between group×subgroup (P=.004). The −0.5 mm location obtained the worst trueness in the margin area. The i700 and Primescan obtained the best trueness in the margin area. Precision discrepancies were found in the preparation area (P<.001). The TRIOS 5 obtained the best precision in the preparation area (P=.001). Precision discrepancies in the margin area were obtained (P<.001). The 1-mm subgroup obtained the best precision (P=.001). ConclusionsThe apical position of the finish line of the tooth preparation tested affected the trueness and precision of the IOSs tested.

Barriers to Early Progress in Adult Cochlear Implant Outcomes.

Adult cochlear implant (CI) recipients obtain varying levels of speech perception from their device. Adult CI users adapt quickly to their CI if they have no peripheral "bottom-up" or neurocognitive "top-down" limiting factors. Our objective here was to understand the influence of limiting factors on the progression of sentence understanding in quiet and in noise, initially and over time. We hypothesized that the presence of limiting factors, detected using a short test battery, would predictably influence sentence recognition with practical consequences. We aimed to validate the test battery by comparing the presence of limiting factors and the success criteria of >90% sentence understanding in quiet 1 month after activation. The study was a single-clinic, cross-sectional, retrospective design incorporating 32 adult unilateral Nucleus CI users aged 27 to 90 years (mean = 70, SD = 13.5). Postoperative outcome was assessed through sentence recognition scores in quiet and in varying signal to noise ratios at 1 day, 1 to 2 months, and up to 2 years. Our clinic's standard test battery comprises physiological and neurocognitive measures. Physiological measures included electrically evoked compound action potentials for recovery function, spread of excitation, and polarity effect. To evaluate general cognitive function, inhibition, and phonological awareness, the Montreal Cognitive Assessment screening test, the Stroop Color-Word Test, and tests 3 and 4 of the French Assessment of Reading Skills in Adults over 16 years of age, respectively were performed. Physiological scores were considered abnormal, and therefore limiting, when total neural recovery periods and polarity effects, for both apical and basal electrode positions, were >1.65 SDs from the population mean. A spread of excitation of >6 electrode units was also considered limiting. For the neurocognitive tests, scores poorer than 1.65 SDs from published normal population means were considered limiting. At 1 month, 13 out of 32 CI users scored ≥90% sentence recognition in quiet with no significant dependence on age. Subjects with no limiting peripheral or neurocognitive factors were 8.5 times more likely to achieve ≥90% score in quiet at 1 month after CI switch-on (p = 0.010). In our sample, we detected 4 out of 32 cases with peripheral limiting factors that related to neural health or poor electrode-neural interface at both apical and basal positions. In contrast, neurocognitive limiting factors were identified in 14 out of 32 subjects. Early sentence recognition scores were predictive of long-term sentence recognition thresholds in noise such that limiting factors appeared to be of continuous influence. Both peripheral and neurocognitive processing factors affect early sentence recognition after CI activation. Peripheral limiting factors may have been detected less often than neurocognitive limiting factors because they were defined using sample-based criteria versus normal population-based criteria. Early performance was generally predictive of long-term performance. Understanding the measurable covariables that limit CI performance may inform follow-up and improve counseling. A score of ≥90% for sentence recognition in quiet at 1 month may be used to define successful progress; whereas, lower scores indicate the need for diagnostic testing and ongoing rehabilitation. Our findings suggest that sentence test scores as early as 1 day after activation can provide vital information for the new CI user and indicate the need for rehabilitation follow-up.

1-(Anthracen-9-ylmeth-yl)-1,4,7,10-tetra-aza-cyclododeca-ne]chlorido-zinc(II) nitrate.

In the title salt, [ZnCl(C23H30N4)]NO3, the central ZnII atom of the complex cation is coordinated in a square-pyramidal arrangement by four nitro-gen atoms from cyclen (1,4,7,10-tetra-aza-cyclo-dodeca-ne) in the basal plane and one chlorido ligand in the apical position. The anthracene group attached to cyclen contributes to the crystal packing through inter-molecular T-shaped π inter-actions. Additionally, the nitrate anion participates in inter-molecular N-H⋯O hydrogen bonds with cyclen.

A novel one-dimensional thiocyanate-bridged cobalt(III) complex: synthesis, crystal structure characterization and Hirshfeld surface analysis.

A new one-dimensional thiocyanate-bridged cobalt(III) Schiff base complex, namely, catena-poly[[[4-bromo-2-((Z)-{[2-(thiophen-2-yl)ethyl]imino}methyl)phenolato-κ2N,O]cobalt(III)]-μ-thiocyanato-κ2N:S], [Co(SCN)(C13H11BrNOS)2]n or [Co(μ1,3-SCN)L2]n (1), where HL is 4-bromo-2-((Z)-{[2-(thiophene-2-yl)ethyl]imino}methyl)phenol, a bidentate Schiff base prepared from the condensation reaction of 5-bromosalicylaldehyde and 2-(thiophen-2-yl)ethylamine, has been synthesized by stirring Co(ClO4)2·6H2O, the Schiff base HL and ammonium thiocyanate (in a 1:2:1 molar ratio) in ethanol medium. The complex was characterized by FT-IR, electronic spectra and single-crystal X-ray diffraction (SC-XRD) studies. The SC-XRD data suggest that the compound crystallizes in the orthorhombic space group Pca21. The CoIII ion in 1 adopts a distorted octahedral geometry, the metal sites being six-coordinated by one thiocyanate N atom and one thiocyanate S atom in apical positions, and by two imine N atoms and two phenolate O atoms from two anionic L- ligands which form the basal plane. The thiocyanate ligand acts as a μ-1,3 bridge, joining neighbouring CoIII atoms and forming a uniform zigzag one-dimensional polymeric chain. The crystallographic data were also used in the Hirshfeld surface (HS) analysis, which aimed to investigate the nature and quantitative significance of any noncovalent intermolecular interactions inside the crystal lattice. The crystal void parameters have also been computed and show the molecules to be tightly packed.

Comprehensive Exploration of Optics and Magnetism in a Hydrothermally Synthesized Nickel(II) Complex.

The hydrothermal reaction of 2-MeIm (2-MeIm: 2-methylimidazole) with nickel sulfate hexahydrate in methanol afforded a mononuclear complex formulated as [Ni(SO4)(2-MeIm)2(H2O)3]·CH3OH (1). The title compound was described by X-ray single-crystal diffraction, thermal assessment, IR, and UV-vis spectroscopy. The crystal structure of 1 is composed of segregated [Ni(SO4)(2-MeIm)2(H2O)3] neutral entities and a solvent methanol molecule. Two (2-MeIm) ligands, a sulfate group, and a water molecule reside in the equatorial positions of the vertices in this 6-fold coordination. Two aqua ligands lay in the apical positions, resulting in a subtly distorted octahedral framework, as was supported by spectroscopic analysis. The complex's self-assembly is firmly governed by robust O-H···O/N-H···O interactions. Further details on these bonds have been furnished via Hirshfeld surface scrutiny and 2D fingerprint plots. As proven by TGA/DSC analysis, raising the temperature of 1 above 60 °C instigates progressive decomposition stages, which culminates in the production of metal oxide as the ultimate product at 700 °C. The optical analysis suggests the dielectric nature of the material with large direct and indirect gap energies of 5.25 and 4.96 eV, respectively. The results of magnetic studies suggest that 1 undergoes a transition to a magnetically ordered state below 6 K.

Synthetic route for O,S‐coordinated organotin (IV) aldehydes: Spectroscopic, computational, XRD, and antibacterial studies

Numerous synthetic routes have been established for the synthesis of organotin (IV) derivatives of carboxylates, thiocarbamates, thiols, alcohols, amines, Schiff bases, etc. However, no synthetic path has been still developed for the synthesis of organotin (IV) aldehydes. We have synthesized four O,S‐coordinated organotin (IV) aldehydes (1–4) of the general formulas LSn(S)(Cl)R2 (where R2 = Me2, n‐Bu2, Ph2 for 1–3, respectively) and LSn(S)Ph3 (4) by reaction of 4‐(dimethylamino)benzaldehyde (L) with KOH, CS2, and R2SnCl2/Ph3SnCl in methanol. The synthesized products were characterized by microanalysis (CHN), FT‐IR analysis, UV–visible spectroscopy, NMR spectroscopy (1H and 13C), thermogravimetric analysis (TGA), computational studies, and single‐crystal XRD. Elemental analysis data were agreed well with the molecular composition of the products. FT‐IR spectroscopy has shown a significant lowering of C=O vibrational frequency after ligand–metal coordination. The electronic spectroscopy of complexes 1–4 demonstrated the π–π* (342–343 nm) and n–π* (279–296 nm) transitions, with the band gap values of 3.15–3.38 eV. 1H NMR spectra displayed distinct signals for the ligand skeleton and organotin (IV) moieties. 13C NMR spectroscopy exhibited an upfield shift of carbonyl oxygen after ligand–metal coordination. The thermogravimetric analysis revealed the thermal stabilities of complexes up to a temperature of 190 to 320°C. Single‐crystal XRD analysis of product 4 has shown a distorted trigonal bipyramidal geometry around Sn (IV), in which the three phenyl groups were positioned equatorially while the carbonyl oxygen (from the aldehyde) and the sulfur atom occupied the apical positions. Employing the 6‐31G(d,p) basis set and the CAM‐B3LYP functional, time‐dependent density functional theory (TD‐DFT) computations were performed for the calculation of absorbance maxima, oscillator strength (f), and matching molecular designations. MEP maps and HOMO–LUMO energy gaps were predicated on the CAM‐B3LYP/6‐31+g(d,p) level of theory and were used to resolve GRD, including chemical potential (μ), global hardness (η), global softness (S), electronegativity (χ), electrophilicity (ω), ionization potential (IP), and electron affinity (EA). The phenyltin (IV) derivatives (3 and 4) have shown a fantastic biofilm inhibition of Escherichia coli, which was even higher as compared with that of the reference drug ciprofloxacin. The bioactivity of 2 against Bacillus subtilis was equivalent to that of the ciprofloxacin. The products 2 and 3 have shown very little (less than 10%) toxic hemolytic effects demonstrating their possible safe use for the human beings.

CASE STUDY OF NORMAL ECHOCARDIOGRAPHYIN AN ADULT SIBERIAN HUSKY DOG

Echocardiography is commonly used in veterinary medicine to assess cardiac structure and function in dogs. This case study was aimed to evaluate normal echocardiography of an adult Siberian Husky. Standard techniques, including B-Mode, M-Mode, and Color Flow Doppler, were carried out by using the Acclarix AX3 Vet USG and a micro convex probe 5-9 MHz. Examinations were conducted in the right parasternal and left apical positions. The results indicate that the six-year-old, 32 kg Siberian Husky in this study exhibited a normal heart. When comparing M-Mode echocardiography with the normal range for dogs of similar size, role, and weight, left ventricular internal dimension in diastole (LVIDd) was below the normal range, while left ventricular posterior wall in diastole (LVWPd) and left ventricular posterior wall in systole (LVPWs) were higher. These findings highlight the necessity for breed-specific reference intervals. This case study emphasizes the correlation between the normal echocardiography interpretation and canine cardiac function, as depicted by the value of ejection fraction (EF) 66.04% and fractional shortening (FS) 35.52%. The echocardiography results of the Siberian Husky in the study are comparable to reference interval values of similar breeds that are working dogs, making them valuable as reference values for future studies.

Chlorido-[5,10,15,20-tetra-kis-(quinoline-7-carboxamido)-porphinato]iron(III).

The title compound, [Fe(C84H52N12O4)Cl], crystallizes in space group C2/c. The central FeIII cation (site symmetry 2) is coordinated in a fivefold manner, with four pyrrole N atoms of the porphyrin core in the basal sites and one Cl atom (site symmetry 2) in the apical position, which completes a slightly distorted square-pyramidal environment. The porphyrin macrocycle shows a characteristic ruffled-shape distortion and the iron atom is displaced out of the porphyrin plane by 0.42 Å with the average Fe-N distance being 2.054 (4) Å; the Fe-Cl bond length is 2.2042 (7) Å. Inter-molecular C-H⋯N and C-H⋯O hydrogen bonds occur in the crystal structure.

A novel score predictor for atrial fibrillation in cardiac implantable electronic device patients

Abstract Background Atrial fibrillation (AF) in individuals with cardiac implantable electronic devices is associated with heightened risks of adverse outcomes. Despite this, risk stratification for AF development in this patient cohort remains unexplored. Consequently, we present the development and validation of a simplified multi-parameter risk-based scoring system for predicting AF in patients with cardiac implantable electronic devices. Methods and Results A cohort of 226 consecutive patients with cardiac implantable electronic devices at Rajavithi Hospital underwent comprehensive follow-up to observe AF development, defined by 12-lead EKG evidence of AF. Analysis encompassed risk factors and AF incidence. The resulting V-DASH score integrated a History of vascular disease, including coronary artery disease (CAD) and peripheral arterial disease (PAD) (1.5 points), Diabetes (1 point), Apical lead position (1 point), Sex (female gender (1.5 points)), and Hypertension (1 point). Predictive value assessment revealed that Diabetes, Female gender, and a history of vascular disease were significantly associated with AF incidence. Apical lead position and Hypertension emerged as robust risk factors for AF development. Over a median follow-up duration of 13 months, 8 (3.53%) patients developed AF. The incidence of AF exhibited a noteworthy escalation in correlation with the V-DASH score (4.68 times higher risk per point increase). Among patients with a V-DASH score ≥4, the probability of AF occurrence was 97.34%. The V-DASH score demonstrated exceptional predictive capability (area under the curve, 0.90; 95% CI, 0.79–1.00), calibration ability (Hosmer-Lemeshow goodness-of-fit P=0.552), and accuracy (sensitivity 87.50% and specificity 83.94%), surpassing other clinical scores such as the C2HEST score. Conclusions The V-DASH score emerged as a robust predictor of AF incidence in patients with cardiac implantable electronic devices, with the highest risk observed in those with a V-DASH score ≥4. The potential clinical utility of the V-DASH score in this patient population warrants further investigation.ROC curve for predicting AFPerformance calibration plot

Aluminagerma[5]pyramidanes-Formation and Skeletal Rearrangement.

The salt metathesis reaction of dipotassium germacyclopentadienediide with aluminum(III) dichlorides provides either half-sandwich alumole complexes of germanium(II) or aluminylene germole complexes. Their molecular structure and the delocalized bonding situation, revealed by density functional theory (DFT) calculations, are equally described as isomeric aluminagerma[5]pyramidanes with either the germanium or the aluminum atom in the apical position of the pentagonal pyramid. The product formation and the selectivity of the reaction depends on the third substituent of the aluminum dichloride. Aryl-substituents favor the formation of alumole complexes and Cp*-substituents that of the isomeric germole complexes. With amino-substituents at the aluminum atom mixtures of both isomers are formed and the positional exchange of the two heteroatoms is shown by NMR spectroscopy. The alumole complexes of germanium(II) undergo facile reductive elimination of germanium and form the corresponding alumoles.

Aluminagerma[5]pyramidane – Bildung und Gerüstumlagerung

AbstractSalzmetathesereaktionen zwischen Dikaliumgermacyclopentadiendiiden und Aluminium(III)dichloriden ermöglichen die Synthese von Alumol‐Halbsandwichkomplexen des zweiwertigen Germaniums oder von Aluminylen‐Germol‐Komplexen. Deren Molekülstrukturen und ihre delokalisierte Bindungssituation, wie sie durch Dichtefunktionalrechnungen (DFT) belegt wird, erlauben gleichermaßen ihre Beschreibung als isomere Aluminagerma[5]pyramidane mit entweder dem Germanium‐ oder dem Aluminiumatom in der apikalen Position der pentagonalen Pyramide. Die Produktbildung und die Selektivität der Reaktion hängen von dem dritten Substituenten des Aluminiumdichlorids ab. Arylgruppen begünstigen die Bildung von Alumolkomplexen und der Cp*‐Substituent die der isomeren Germolkomplexe. Mit Aminosubstituenten am Aluminiumatom werden Mischungen beider Isomere erhalten, wobei der Austausch der Positionen der beiden Heteroatome im Pyramidan durch NMR Spektroskopie nachgewiesen wurde. Zudem können, ausgehend von Alumolkomplexen des zweiwertigen Germaniums, durch reduktive Eliminierung des Germaniums die entsprechenden Alumole erhalten werden.

{N-[1-(2-Oxidophen-yl)ethyl-idene]-dl-alaninato}(pentane-1,5-di-yl)silicon(IV).

The title SiIV complex, C16H21NO3Si, is built up by a tridentate dinegative Schiff base ligand bound to a sila-cyclo-hexane unit. The coordination geometry of the penta-coordinated SiIV atom is a distorted trigonal bipyramid. The presence of the sila-cyclo-hexane ring in the complex leads to an unusual coordination geometry of the SiIV atom with the N atom from the Schiff base ligand and an alkyl-C atom in apical positions of the trigonal bipyramid. There is a disorder of the methyl group at the imine bond with two orientations resolved for the H atoms [major orientation = 0.55 (3)]. In the crystal, C-H⋯O inter-actions are found within corrugated layers of mol-ecules parallel to the ab plane.

A new copper(II) complex containing long-chain aliphatic hydrazide and 1,10-phenanthroline upregulates ADP hydrolysis in triple-negative breast cancer cells

Copper can be opportunely complexed to modulate oncogenic pathways, being a promising strategy for cancer treatment. Herein, three new copper(II) complexes containing long-chain aliphatic hydrazides and 1,10-phenanthroline (1,10-phen), namely, [Cu(octh)(1,10-phen)(H2O)](NO3)21, [Cu(dech)(1,10-phen)(H2O)](NO3)22 and [Cu(dodh)(1,10-phen)(H2O)](NO3)2.H2O 3 (where octh = octanoic hydrazide, dech = decanoic hydrazide, dodh = dodecanoic hydrazide) were successfully prepared and characterized by several physical-chemical methods. Furthermore, X-ray structural analysis of complex 2 indicated that the geometry around the copper(II) ion is distorted square-pyramidal, in which hydrazide and 1,10-phenanthroline act as bidentate ligands. A water molecule in the apical position completes the coordination sphere of the metal ion. All new copper(II) complexes were cytotoxic to breast cancer cell lines (MCF7, MDA-MB-453, MDA-MB-231, and MDA-MB-157) and selective when compared to the non tumor lineage MCF-10A. In particular, complex 2 showed half-maximal inhibitory concentration (IC50) values ranging between 2.7 and 13.4 μM in MDA-MB231 cells after 24 and 48 h of treatment, respectively. Furthermore, this complex proved to be more selective for tumor cell lines when compared to doxorubicin and docetaxel. Complex 2 inhibited the clonogenicity of MDA-MB231 cells, increasing adenosine diphosphate (ADP) hydrolysis and upregulating ecto-nucleoside triphosphate diphosphohydrolase 1 (ENTPD1) transcriptional levels. In this sense, we suggest that the inhibitory effect on cell proliferation may be related to the modulation of adenosine monophosphate (AMP) levels. Thus, a novel copper(II) complex with increased cytotoxic effects and selectivity against breast cancer cells was obtained, contributing to medicinal chemistry efforts toward the development of new chemotherapeutic agents.

Budding and regeneration potential of a calyx of a freshwater Kamptozoan, Urnatella gracilis.

There are only two freshwater Kamptozoans worldwide: Urnatella gracilis Leidy, 1851 and Loxosomatoides sirindhornae Wood, 2005. U. gracilis is present in Japan and is expanding its distribution, especially in Lake Hachiro. We investigated the budding and regeneration potential of a calyx of U. gracilis to clarify the mechanisms underlying its ability of regeneration. Our experiments revealed that the formation of a new calyx at the most apical position and strong adaptation to freshwater in pH 7.0. Budding successfully occurred in water with 0% salinity, however, in water with 0.15%-0.3% salinity budding was occurred in low level. These features may be very useful for propagation at Lake Hachiro in which it has to be expected that no sexual reproduction is observed because of low temperatures below 28°C. Now as Lake Hachiro has water with no salinity and almost pH 7.0, Lake Hachiro is a good place to live for U. gracilis.