The kinetics of conversion of an edge-linked double cube, in this case [{Mo(3)PdS(4)(H(2)O)(9)}(2)](8+), to the corresponding single cube [Mo(3)(PdX)S(4)(H(2)O)(9)](4+), has been studied for the first time. Reaction is induced by six reagents X = CO, two water-soluble phosphines, Cl(-), Br(-), and NCS(-), which complex at the tetrahedral Pd. The first stage of reaction is fast and is accompanied by color changes, e.g. purple to dark blue in the case of Cl(-), assigned as double to single cube conversion. With X = CO and the two phosphines, when absorbance changes are intense enough for stopped-flow monitoring with reactants at =1 mM, rate constants 10(-)(5) k/M(-)(1) s(-)(1) at 25 degrees C are as follows: CO, 1.11; PTA, 27.8; P(C(6)H(4)SO(3))(3)(3)(-), 9.6; at I = 2.00 (Li(pts)). The reactions are independent of [H(+)] in the range 0.30-2.00 M, and no substitution at the Mo's is observed. The first stages with X = Cl(-), Br(-), and NCS(-) were too fast to monitor, but equilibrium constants K(1)/M(-)(1) were determined, Cl(-) (490), Br(-) (8040), and NCS(-) (630), by UV-vis spectrophotometry. Two subsequent kinetic stages are assigned to substitution at the Mo's. Similar behavior is observed for [Mo(3)FeS(4)(H(2)O)(10)](4+), which was selected because substitution at the Fe is also fast and there is no known double-cube formation. For both Mo(3)Pd and Mo(3)Fe the latter two stages can be explained by substitution at nonidentical (two alpha and one beta) H(2)O's on each Mo or by the presence of mixed-valent Mo(III)(2)Mo(IV) forms which are sufficiently long-lived to give a kinetic discrimination. In the case of NCS(-) an additional step, 0.015 s(-)(1), independent of [NCS(-)] is assigned to the isomerization Pd-NCS --> Pd-SCN. On removal of e.g. Cl(-) by chromatography or addition of Ag(+), the double cube re-forms.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ic951595f | DOI Listing |
Chem Sci
January 2025
Department of Chemistry, National Tsing Hua University Hsinchu 300044 Taiwan
PbZrTiO cubes with tunable sizes and cuboids have been hydrothermally synthesized. PbZrTiO cubes with three different Zr : Ti atomic percentages were also prepared. Analysis of synchrotron X-ray diffraction (XRD) patterns reveals the presence of two lattice components for these samples.
View Article and Find Full Text PDFPsychon Bull Rev
January 2025
Department of Education and Psychology, The Open University, 1 University Road, P.O. Box 808, 4353701, Ra'anana, Israel.
Visual perspective taking often involves transitioning between perspectives, yet the cognitive mechanisms underlying this process remain unclear. The current study draws on insights from task- and language-switching research to address this gap. In Experiment 1, 79 participants judged the perspective of an avatar positioned in various locations, observing either the rectangular or the square side of a rectangular cube hanging from the ceiling.
View Article and Find Full Text PDFInorg Chem
January 2025
School of Chemistry, University of Hyderabad, Hyderabad500046, India.
A Ce(III) phosphinate and a Ce(IV) phosphostibonate have been assembled by the reaction of a phosphinic acid and phosphostibonate with Ce(III) salts. Single crystal X-ray diffraction (SCXRD) studies reveal the formation of a rare triangular Ce(III) oxo-cluster [Ce(PhCHPO)]Cl(CHOH)(HO)] () and a fascinating hexanuclear oxo-cluster containing Ce(IV) ions [Ce (-ClCHSb)(μ-O)(μ-O)(-BuPO)(μ-OCH)] (). The molecular architecture of showcased an interesting correlation with platonic solids, wherein the Ce(IV), Sb(V), and P(V) ions were found to be present in vertices of an octahedron, a tetrahedron, and a cube, respectively.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
December 2024
Department of Translational Biomedicine and Neuroscience - DiBraiN, University of Bari "Aldo Moro", Place G. Cesare, 70124, Italy. Electronic address:
Background: Magnesium (Mg) and its alloys are promising candidates for biodegradable materials in next-generation bone implants due to their favourable mechanical properties and biodegradability. However, their rapid degradation and corrosion, potentially leading to toxic byproducts, pose significant challenges for widespread use.
Objectives: This study aimed to address the challenges associated with Mg-based materials by thoroughly evaluating the biocompatibility, genotoxicity, and mechanical properties of Mg-based devices manufactured via Single Point Incremental Forming (SPIF).
Eur J Obstet Gynecol Reprod Biol X
December 2024
Department of Obstetrics and Gynecology, Maruyama Memorial General Hospital, 2-10-5, Honchou, Iwatsuki-ku, Saitama City, Saitama 339-8521, Japan.
Objective: To reduce the damage of uterine endometrium caused during hysteroscopic myomectomy (HM) for reproductive aged patients, a new uterine endometrium preservation hysteroscopic myomectomy (UEP-HM) has been developed. In this study, we introduced this technique with comparing to the conventional hysteroscopic myomectomy (C-HM).
Study Design: The data from 94 patients aged 42 or younger who underwent HM (38 cases with UEP-HM and 56 cases with C-HM) for treating single Type 1 or Type 2 submucosal leiomyoma (SL) were analysed retrospectively for comparing the characteristics of both patient and target SL.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!