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Recent progress in beryllium organometallic chemistry. Chem Commun (Camb) 2024; 60:1663-1673. [PMID: 38260953 DOI: 10.1039/d3cc04844f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Beryllium possesses a unique amalgamation of characteristics, its electronegativity included, that not only make it a vital component in a wide range of technical sectors and consumer industries, but also make it an interesting candidate for forming covalently bonded compounds. However, the extremely toxic nature of beryllium, which can cause chronic beryllium disease, has limited the exploration of its chemistry, making beryllium one of the least studied (non-radioactive) elements. The development of selective chelating ligands, sterically encumbered substituents and, moreover, the boom of N-heterocyclic carbenes in organometallic chemistry and main group chemistry has revived the interest in beryllium chemistry. Therefore, some quite remarkable progress in the coordination and organometallic chemistry of beryllium has been made in the last two decades. For example, low oxidation state beryllium compounds, antiaromatic/aromatic beryllium compounds, where beryllium is involved in π-electron delocalization, and the isolation of beryllium-beryllium bonded species have all been achieved. This article provides an oversight over the recent developments in the organometallic chemistry of beryllium.
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Recent Advances in the Synthesis and Reactivity of Transition Metal σ-Borane/Borate Complexes. Acc Chem Res 2021; 54:1260-1273. [PMID: 33565872 DOI: 10.1021/acs.accounts.0c00819] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The coordination of an element-element σ bond to a transition metal (TM) is both a fundamentally intriguing binding mode and of critical importance to metal-mediated bond activation mechanisms and catalysis, particularly the hotly contested field of C-H activation. TM σ complexes of dihydrogen (i.e., H-H) and silanes (H-SiR3) have been extensively studied, the latter being of interest as models for the (generally unstable and unisolable) σ complexes of alkanes (i.e., H-CR3). TM σ complexes of hydroboranes and hydroborates (i.e., H-BR2, H-BR3, (H-)2BR2) are somewhat less well studied but similarly have relevance to catalytic borylation reactions that are of high current interest to organic synthesis. Our two research groups have made significant contributions to elaborating the family of σ-borane/-borate complexes using two distinct approaches: while the Ghosh group generally starts from hydrogen-rich tetracoordinate boron species such as borates, the Braunschweig group starts from hypovalent and/or hypocoordinate boron building blocks. Through these two approaches, a wide range of species containing one or two σ-bound B-H ligands have been prepared, some with additional chelating donor sites. Over the past 2 years, the body of work on σ-borane/-borate complexes from our two research groups has significantly expanded, with a combined nine published articles in 2019-2020 alone. Very recent work from the Braunschweig group has led to the synthesis of the first bis(σ)-borane complexes of group 6 metals, as well as the synthesis of a series of novel bis(σ)-borane and bis(σ)-borate complexes of ruthenium and iridium, the former being useful precursors for pentacoordinate borylene complexes of Ru. Recent work from the Ghosh group has uncovered a remarkable diversity of structures with σ(B-H)-bound ligands from the combination of borohydrides and nitrogen/chalcogen-containing groups and heterocycles. These reactions, while in some cases producing conventional scorpionate-type chelating products, more frequently undergo fascinating rearrangements with unpredictable outcomes. This Account aims to highlight this recent acceleration of research progress in this area, particularly the distinct but related approaches of-and complexes produced by-our two research groups, in addition to relevant works from other groups where appropriate.
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Abstract
The concepts of aromaticity and antiaromaticity have a long history, and countless demonstrations of these phenomena have been made with molecules based on elements from the p, d, and f blocks of the periodic table. In contrast, the limited oxidation-state flexibility of the s-block metals has long stood in the way of their participation in sophisticated π-bonding arrangements, and truly antiaromatic systems containing s-block metals are altogether absent or remain poorly defined. Using spectroscopic, structural, and computational techniques, we present herein the synthesis and authentication of a heterocyclic compound containing the alkaline earth metal beryllium that exhibits significant antiaromaticity, and detail its chemical reduction and Lewis-base-coordination chemistry.
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Correlation of eGFR By MDRD and CKD-EPI Formula with Creatinine Clearance Estimation in CKD Patients and Healthy Subjects. Mymensingh Med J 2021; 30:35-42. [PMID: 33397848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This cross sectional comparative study was conducted in the Nephrology and Medicine outdoor and in-patients department of Mymensingh Medical College Hospital, Bangladesh from April 2014 to March 2015. A total of 100 patients with CKD and 100 healthy subjects were included in the study. Data were collected by interview of the patients, clinical examination and laboratory investigations using a semi-structured case record form. Among all subjects, 50.0% had no CKD and 50.0% patients had CKD: Stage 3 CKD were 8.5%, CKD Stage 4 CKD were 21.0%, CKD Stage 5 CKD were 20.5%. Serum creatinine was 4.32±3.08mg/dl in patients with CKD and 1.00±0.22mg/dl was in healthy subjects. Mean±SD of CCR/ml/min was found 17.67±11.63ml/min in patients with CKD and 79.31±13.31ml/min was found in healthy subjects. On the other hand, Mean±SD CCCR/ml/m/1.73m² was found 19.79±12.85 ml/m/1.73m² in patient with CKD and healthy subjects had 83.83±13.33 ml/m/1.73m². Urinary creatinine was 45.59±15.63 & 57.66±11.45mg/dl respectively. CKD-EPI eGFR was 22.10±15.02 & 90.61±23.27ml/m/1.73m²; MDRD eGFR was 22.15±14.18 & 89.35±26.19 ml/m/1.73m² respectively. Difference between all the variables between CKD group and healthy group was found statistically significant (p<0.001). CKD-EPIeGFR and MDRDeGFR were increased both in CKD patients and healthy subjects in respect to CCR and CCCR. There was a strong positive correlation between CCCR (ml/m/1.73m2) and CKD-EPI (ml/m/1.73m²) among all patients (r=0.934 and p<0.001) and also a positive correlation of CCCR with MDRD among all patients (r=0.913 and p<0.001). A positive correlation of CCCR was found with CKD-EPIeGFR among CKD patients (r=0.848 and p<0.001). A positive correlation of CCCR was also found with MDRDeGFR among CKD patients (r=0.841, p<0.001). There are positive correlations between CCCR and CKD/EPI among healthy subjects (r=0.616 and p<0.05) and between CCCR with MDRD among healthy subjects (r=0.568 and p<0.05). Various formulae were used to calculate GFR on the basis of serum creatinine levels. The Overall correlation of population (healthy and CKD patients) between CCCR and CKD EPI and MDRD formula was (r=0.93 and 0.91) respectively, among CKD patients it was (r=0.848 and r=0.841) in healthy subjects it was (r=0.616 and r=0.568) respectively. CKD EPI eGFR and MDRD eGFR formula had fairly good correlation with conventional 24 hours creatinine clearance in both CKD patient and healthy subjects, there was even more strong correlation especially in CKD patients. The performance of CKD-EPI equation is better than MDRD equation to estimate the eGFR in both CKD patients and healthy subjects.
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Toward Transition-Metal-Templated Construction of Arylated B 4 Chains by Dihydroborane Dehydrocoupling. Chemistry 2019; 25:16544-16549. [PMID: 31663648 PMCID: PMC6972581 DOI: 10.1002/chem.201904772] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Indexed: 01/24/2023]
Abstract
The reactivity of a diruthenium tetrahydride complex towards three selected dihydroboranes was investigated. The use of [DurBH2 ] (Dur=2,3,5,6-Me4 C6 H) and [(Me3 Si)2 NBH2 ] led to the formation of bridging borylene complexes of the form [(Cp*RuH)2 BR] (Cp*=C5 Me5 ; 1 a: R=Dur; 1 b: R=N(SiMe3 )2 ) through oxidative addition of the B-H bonds with concomitant hydrogen liberation. Employing the more electron-deficient dihydroborane [3,5-(CF3 )2 -C6 H3 BH2 ] led to the formation of an anionic complex bearing a tetraarylated chain of four boron atoms, namely Li(THF)4 [(Cp*Ru)2 B4 H5 (3,5-(CF3 )2 C6 H3 )4 ] (4), through an unusual, incomplete threefold dehydrocoupling process. A comparative theoretical investigation of the bonding in a simplified model of 4 and the analogous complex nido-[1,2(Cp*Ru)2 (μ-H)B4 H9 ] (I) indicates that there appear to be no classical σ-bonds between the boron atoms in complex I, whereas in the case of 4 the B4 chain better resembles a network of three B-B σ bonds, the central bond being significantly weaker than the other two.
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Exploiting silver trifluoromethanesulfonate as efficient and reusable catalyst for the synthesis of dihydropyrimidine derivatives under different reaction environments. J Heterocycl Chem 2019. [DOI: 10.1002/jhet.3728] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Congenital Eventration of Diaphragm Presenting As Diaphragmatic Hernia: A Case Report. Mymensingh Med J 2019; 28:952-956. [PMID: 31599268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Eventration of diaphragm is an abnormal elevation of diaphragmatic musculature while retaining normal attachments to the sternum, ribs and dorsolumber spine. It is a rare anomaly where the continuity of diaphragm remains intact. Pathological process can affect either all or only a portion of hemidiaphragm. Symptoms vary according to size of the defect. Large defect may mimic diaphragmatic hernia. The present case represents a full term female newborn that developed respiratory distress, cyanosis and feeding difficulties since 1st day of life. Clinical features and chest imaging of this case was assumed to be left sided diaphragmatic hernia which was found wrong in the operation theater. She was found to have left sided eventration of diaphragm to create symptom. Successful plication of ipsilateral diaphragm was done on 13th day of life. Supervised post operative ventilatory support along with other postoperative care improved the condition of this neonate. A large defect with eventration of diaphragm may be life threatening but a timely good management can save neonate from such condition.
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Steric Effects Dictate the Formation of Terminal Arylborylene Complexes of Ruthenium from Dihydroboranes. Chemistry 2019; 25:13566-13571. [PMID: 31433081 PMCID: PMC7079023 DOI: 10.1002/chem.201902890] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Indexed: 11/08/2022]
Abstract
The steric and electronic properties of aryl substituents in monoaryl borohydrides (Li[ArBH3 ]) and dihydroboranes were systematically varied and their reactions with [Ru(PCy3 )2 HCl(H2 )] (Cy: cyclohexyl) were studied, resulting in bis(σ)-borane or terminal borylene complexes of ruthenium. These variations allowed for the investigation of the factors involved in the activation of dihydroboranes in the synthesis of terminal borylene complexes. The complexes were studied by multinuclear NMR spectroscopy, mass spectrometry, X-ray diffraction analysis, and density functional theory (DFT) calculations. The experimental and computational results suggest that the ortho-substitution of the aryl groups is necessary for the formation of terminal borylene complexes.
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First Bis(σ)‐borane Complexes of Group 6 Transition Metals: Experimental and Theoretical Studies. Chemistry 2019; 25:8585-8589. [DOI: 10.1002/chem.201901075] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Indexed: 11/10/2022]
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New Outcomes of Beryllium Chemistry: Lewis Base Adducts for Salt Elimination Reactions. Inorg Chem 2019; 58:2652-2658. [DOI: 10.1021/acs.inorgchem.8b03263] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Selective one- and two-electron reductions of a haloborane enabled by a π-withdrawing carbene ligand. Chem Commun (Camb) 2018; 54:9015-9018. [PMID: 30046799 DOI: 10.1039/c8cc03433h] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A carbene-stabilised neutral boryl radical and a boryl anion are isolated via selective one- and two-electron reduction of a diamidocarbene (DAC) adduct of dibromo(pentafluorophenyl)borane. Both the radical and the anion have been characterised by various spectroscopic techniques in solution, while the structures have been ascertained by single-crystal X-ray diffraction. In contrast, the reduction of the analogous cyclic (alkyl)(amino) carbene (CAAC) adduct yields a C-H activation product.
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Plasma Neutrophil Gelatinase Associated Lipocalin (pNGAL) Level to Identify AKI Early in Patients Undergoing Cardiac Valve Surgery. Mymensingh Med J 2018; 27:263-269. [PMID: 29769488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cardiac valve surgery is considered one of the most frequent surgical procedures in which AKI is a common & serious complication. Although serum creatinine is routinely used as a marker of renal function, it poorly reflects the immediate post operative period renal function. Within minutes to few hours after a renal insult, plasma neutrophil gelatinase associated lipocalin (pNGAL) is released. The aim of this study was to assess the superiority of pNGAL over serum creatinine in detecting AKI in early post operative period. This prospective observational study was carried out in the Department of Nephrology of National Institute of Kidney Diseases & Urology in collaboration with National Institute of Cardiovascular Diseases (NICVD) & Dhaka Shisu Hospital (DSH) from January 2015 to December 2016. Total 120 patients were selected from inpatient ward of cardiovascular surgery department. According to inclusion & exclusion criteria total 80 patients were included who was undergone cardiac valve surgery. Serum samples for pNGAL were collected from study population 6 hours after completion of surgery & stored at -80°C, serum samples were also collected for serum creatinine day before surgery, in 1st post operative day (POD1) & 2nd post operative day (POD2). Total 79 patients undergoing cardiac surgery, who met the inclusion & exclusion criteria, were consecutively included. There were 44 male (55.69%) and 35 female (40.31%) ranged from 15-60 years, with mean age of 36 years. pNGAL level in the blood of AKI patients (244.19±59.61ng/ml) 6 hours after completion of surgery was significantly higher from the non AKI patients (171.73±68.63ng/ml). A positive significant correlation was found between pNGAL 6 hours after completion of surgery & serum creatinine at POD1, POD2. This study demonstrated that level of pNGAL concentration 6 hours after completion of cardiac valve surgery increased before the rise of serum creatinine level & can thus AKI can be detected earlier by pNGAL.
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Heterodimetallaboranes of Group 4 and 9 Metals: Analogues of Pentaborane(11) and Hexaborane(12). Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700330] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Cover Feature: Recent Developments in Azaborinine Chemistry (Eur. J. Inorg. Chem. 38‐39/2017). Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201701120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Acute Kidney Injury in Patients with Acute Viral Hepatitis: A Study in a Tertiary Care Hospital. Mymensingh Med J 2017; 26:790-796. [PMID: 29208866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This cross sectional observational study was done in the Department of Medicine, Mymensingh Medical College Hospital (MMCH), Mymensingh, Bangladesh from May 2013 to April 2014 to find out the proportion of acute kidney injury among patients with acute viral hepatitis and to identify risk factors associated with development of acute kidney injury (AKI). A total of 100 patients with acute viral hepatitis were included purposively as study subjects. Among them 61 were male and 39 were female. They were divided into AKI group (n=6) and non-AKI group (n=94) on the basis of development of AKI. There was no significant difference in mean age (39.0±13.1 years vs. 32.2±10.8 years, p=0.335) and sex (67% vs. 61% & 33.0% vs. 39.0%) p=0.769) between AKI group and non-AKI group. There were 27% acute viral hepatitis A, 21% acute viral hepatitis B and 52% acute viral hepatitis E but no case of acute viral hepatitis C was found in this study. Acute kidney injury (AKI) developed in 6 of 27 patients with acute viral hepatitis A. This study showed that 22.2% patients with acute viral hepatitis A developed acute kidney injury but patients with acute viral hepatitis B (HBV) and hepatitis E (HEV) did not develop acute kidney injury. Majority of the patients with acute kidney injury were smokers and hypertensive with elevated mean arterial pressure (p=0.0001) at presentation and had higher total bilirubin (p=0.0001), alanine aminotranseferase values (p=0.040), prolonged prothrombin time (INR) {p=0.0001}, lower albumin (p=0.0001), lower haematocrit level (p=0.0001), high CRP concentration (p=0.0001), leucocytosis (p=0.0001) and thrombocytopenia (p=0.0001) at presentation than patients without acute kidney injury. It is evident from the study that acute kidney injury is not a rare complication in patients with acute viral hepatitis.
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Synthesis and Characterization of Bis(sigma)borate and Bis-zwitterionic Complexes of Rhodium and Iridium. ChemistrySelect 2016. [DOI: 10.1002/slct.201600980] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
A series of novel isocloso-diiridaboranes [(Cp*Ir)2B6H6], 1, 2; [1,7-(Cp*Ir)2B8H8], 4; [1,4-(Cp*Ir)2B8H8], 5; [(Cp*Ir)2B9H9], 8; isonido-[(Cp*Ir)2B7H7], 3; and 10-vertex cluster [5,7-(Cp*Ir)2B8H12], 6 (Cp* = η(5)-C5Me5) have been isolated and structurally characterized from the pyrolysis of [Cp*IrCl2]2 and BH3·thf. On the other hand, the corresponding rhodium system afforded 10- and 11-vertices clusters [5-(Cp*Rh)B9H13)], 7, and [(Cp*Rh)2B9H9], 9, respectively. Clusters 1 and 2 are topological isomers. The geometry of 1 is dodecahedral, similar to that of its parent borane [B8H8](2-), in which two of the [BH] vertices are replaced by two [Cp*Ir] fragments. The geometry of 2 can be derived from a nine-vertex tricapped trigonal prism by removing one of the capped vertices. Compounds 4 and 5 are 10-vertex isocloso clusters based on a 10-vertex bicapped square antiprism structure. The only difference between them is the presence of a metal-metal bond in 5. The solid-state structures of 8 and 9 attain an 11-vertex geometry in which a unique six-membered B6H6 moiety is bonded to the metal center. In addition, quantum-chemical calculations have been used to provide further insight into the electronic structure and stability of the clusters. All the compounds have been characterized by IR and (1)H, (11)B, and (13)C NMR spectroscopy in solution, and the solid-state structures were established by X-ray crystallographic analysis.
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New Routes to a Series of σ-Borane/Borate Complexes of Molybdenum and Ruthenium. Chemistry 2015; 21:17191-5. [DOI: 10.1002/chem.201503404] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Indexed: 11/06/2022]
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Homometallic Cubane Clusters: Participation of Three-Coordinated Hydrogen in 60-Valence Electron Cubane Core. Inorg Chem 2015; 54:8673-8. [PMID: 26347293 DOI: 10.1021/acs.inorgchem.5b01298] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This work describes the synthesis, structural characterizations, and electronic structures of a series of novel homometallic cubane clusters [(Cp*Ru)2{Ru(CO)2}2BH(μ3-E)(μ-H)B(μ-H)3M], (2, M = Cp*Ru, E = CO; 3, M = Ru(Cp*Ru)2(μ-CO)3(μ-H)BH), E = BH), [(Cp*Ru)3(μ3-CO)(BH)3(μ3-H)3], 4, and [(Cp*Ru)2(μ3-CO){Ru(CO)3}2(BH)2(μ-H)B], 5 (Cp* = η(5)-C5Me5). These cubane clusters have been isolated from a thermally driven reaction of diruthenium analogue of pentaborane(9) [(Cp*RuH)2B3H7], 1, and [Ru3(CO)12]. Structural and spectroscopic studies revealed the existence of triply bridged hydrogen (μ3-H) atoms that participate as a vertex in the cubane core formation for compounds 2, 3, and 4. In addition, the crystal structure of these clusters clearly confirms the presence of an electron precise borane ligand (borylene fragment) which is triply bridged to the trimetallic units. Bonding of these novel complexes has been studied computationally by DFT methods, and the studies demonstrate that the cubane clusters 2 and 3 possess 60 cluster valence electrons (cves) with six metal-metal bonds. All the new compounds have been characterized in solution by mass spectrometry; IR; and (1)H, (11)B, and (13)C NMR studies, and the structural types were unequivocally established by crystallographic analysis of compounds 2-5.
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Chemistry of N,S-Heterocyclic Carbene and Metallaboratrane Complexes: A New η3-BCC-Borataallyl Complex. Chemistry 2015; 21:13732-8. [DOI: 10.1002/chem.201501014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Indexed: 11/08/2022]
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Abstract
Correction for ‘Chemistry of group 9 dimetallaborane analogues of octaborane(12)’ by Subrat Kumar Barik, et al., Dalton Trans., 2015, 44, 669–676.
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Back Cover: Chemistry of Diruthenium and Dirhodium Analogues of Pentaborane(9): Synthesis and Characterization of Metal N,S-Heterocyclic Carbene and B-Agostic Complexes (Chem. Eur. J. 9/2015). Chemistry 2015. [DOI: 10.1002/chem.404786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Novel Neutral Zirconaborane [(Cp2Zr)2B5H11]: An arachno-B3H9 Analogue (Cp = η5-C5H5). Organometallics 2015. [DOI: 10.1021/om5012853] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Chemistry of early and late transition metallaboranes: synthesis and structural characterization of periodinated dimolybdaborane [(Cp*Mo)2B4H3I5]. PURE APPL CHEM 2015. [DOI: 10.1515/pac-2014-0720] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThermolysis of an in situ generated intermediate [(Cp*Ta)2(BH3)2Cl2], 1 generated from the reaction of [Cp*TaCl4], (Cp* = η5-C5Me5) and [LiBH4·thf], in presence of [Ru3(CO)12] yielded pileo-[Cp*TaCl(μ-Cl)-B2H4Ru3(CO)8], 2 having two electrons fewer than seven pairs required for the observed square pyramidal geometry. Cluster 2 is the first example of an unsaturated cluster comprising early and late transition metals in a square pyramid core. This reaction also yielded [(Cp*Ta)2(B2H6)(B2H4Cl2)], 3 as a by-product. In addition, the reaction of [Cp*MoCl4] (Cp* = η5-C5Me5) with [LiBH4.thf] in presence of excess [MeI] at mild condition led to the isolation of periodinated dimolybdatetraborane [(Cp*Mo)2B4H3I5], 4 that hints a possible existence of [(Cp*Mo)2B4H8]. After the isolation of periodinated 4, we extended this chemistry towards the late transition metallaborane [(Cp*Rh)3B4H4], 5 using [PtBr2] as brominating source. Although all the attempts to isolate perbrominated rhodaborane failed, we have isolated partially brominated rhodaborane clusters [(Cp*Rh)3(BH)-(BBr)3], 6 and [(Cp*Rh)3(BH)3(BBr)], 7. All the compounds were characterized by IR and 1H, 11B and 13C NMR spectroscopy in solution, and the solid-state structures of 2, 4 and 6 were established by crystallographic analysis.
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Abstract
Reaction of octaborane(12) analogue with metal carbonyl compounds yielded condensed metallaborane (A) and boride cluster (B).
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Chemistry of Diruthenium and Dirhodium Analogues of Pentaborane(9): Synthesis and Characterization of Metal N,S-Heterocyclic Carbene and B-Agostic Complexes. Chemistry 2014; 21:3640-8. [DOI: 10.1002/chem.201405218] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Indexed: 11/08/2022]
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Mixed-metal chalcogenide tetrahedral clusters with an exo-polyhedral metal fragment. Dalton Trans 2014; 43:17184-90. [PMID: 25317933 DOI: 10.1039/c4dt02329c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The reaction of metal carbonyl compounds with group 6 and 8 metallaboranes led us to report the synthesis and structural characterization of several novel mixed-metal chalcogenide tetrahedral clusters. Thermolysis of arachno-[(Cp*RuCO)2B2H6], 1, and [Os3(CO)12] in the presence of 2-methylthiophene yielded [Cp*Ru(CO)2(μ-H){Os3(CO)9}S], 3, and [Cp*Ru(μ-H){Os3(CO)11}], 4. In a similar fashion, the reaction of [(Cp*Mo)2B5H9], 2, with [Ru3(CO)12] and 2-methylthiophene yielded [Cp*Ru(CO)2(μ-H){Ru3(CO)9}S], 5, and conjuncto-[(Cp*Mo)2B5H8(μ-H){Ru3(CO)9}S], 6. Both compounds 3 and 5 can be described as 50-cve (cluster valence electron) mixed-metal chalcogenide clusters, in which a sulfur atom replaces one of the vertices of the tetrahedral core. Compounds 3 and 5 possess a [M3S] tetrahedral core, in which the sulfur is attached to an exo-metal fragment, unique in the [M3S] metal chalcogenide tetrahedral arrangements. All the compounds have been characterized by mass spectrometry, IR, and (1)H, (11)B and (13)C NMR spectroscopy in solution, and the solid state structures were unequivocally established by crystallographic analysis of compounds 3, 5 and 6.
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Reactivity of Diruthenium and Dirhodium Analogues of Pentaborane(9): Agostic versus Boratrane Complexes. Angew Chem Int Ed Engl 2014; 53:2873-7. [DOI: 10.1002/anie.201310416] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 01/08/2014] [Indexed: 11/11/2022]
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Reactivity of Diruthenium and Dirhodium Analogues of Pentaborane(9): Agostic versus Boratrane Complexes. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201310416] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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A Novel Heterometallic μ9-Boride Cluster: Synthesis and Structural Characterization of [(η5-C5Me5Rh)2{Co6(CO)12}(μ-H)(BH)B]. Inorg Chem 2013; 53:667-9. [DOI: 10.1021/ic4021178] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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New Heteronuclear Bridged Borylene Complexes That Were Derived from [{Cp*CoCl}2] and Mono-MetalCarbonyl Fragments. Chemistry 2013; 19:15219-25. [DOI: 10.1002/chem.201302427] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Indexed: 11/06/2022]
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Supraicosahedral Polyhedra in Metallaboranes: Synthesis and Structural Characterization of 12-, 15-, and 16-Vertex Rhodaboranes. Inorg Chem 2013; 52:6705-12. [DOI: 10.1021/ic400761z] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Low serum immunglobulin G (IgG) during nephrosis is a predictor of urinary tract infection (UTI) in children with nephrotic syndrome. Mymensingh Med J 2013; 22:336-341. [PMID: 23715358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Low serum level of IgG, complement C3 and C4 in nephrotic syndrome children may cause increased susceptibility to infection. Serum level of IgG and complements in nephrotic children (NS) with UTI has been analyzed in this cross sectional study. It was carried out in the department of Pediatric nephrology, National Institute of Kidney Diseases & Urology (NIKDU), Dhaka, Bangladesh. The study subjects were followed up prospectively for one year to see and compare the frequency of relapse of NS and UTI. Patients were selected in a nonrandom purposive technique. Nephrotic syndrome children with initial attack between 1-12 year of age were included over a period of one year. The patients were grouped into Group I - UTI positive and Group II - UTI negative depending on urine culture positivity and colony count >10⁵ CFU/ml. Serum IgG and complements C3, C4 levels were done in both groups during nephrosis and were compared. A total of 101 children M: F 1.7:1, mean age 5.96±3.2 years were included in this study. Group I, n=45 vs. Group II, n=56. The mean serum level of IgG was low in Group I (549.91±210.71 vs. 728.64±235.81mg/dl, p<0.001). Serum IgG level less than 700mg/dl was found in 37 vs. 23 children {x² (¹) 17.52 p<0.001, OR=6.63}. Mean serum complement C3 level was also low in Group I (123.09±40.52 vs. 143.38±37.06mg/dl, p<0.05). But complement C3 and C4 level do not carry any risk of developing UTI in nephrotic children. Higher number of children in Group II were at remission (n=24) during follow up, while frequent relapsers were high in Group I (n=22). Increased frequency of UTI attack (88 episodes) was found in Group I children compared to none in Group II during follow up. So low serum level of IgG in children with NS during nephrosis can predict UTI with an odds ratio of 6.63 as well as relapse. Serum level of C3, C4 do not associated with any risk of development of UTI in NS children.
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Reactivity of Dirhodium Analogues of Octaborane-12 and Decaborane-14 towards Transition-Metal Moieties. Organometallics 2013. [DOI: 10.1021/om400055s] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Boron Beyond the Icosahedral Barrier: A 16-Vertex Metallaborane. Angew Chem Int Ed Engl 2013; 52:3222-6. [DOI: 10.1002/anie.201208849] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Indexed: 11/07/2022]
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Syntheses and characterization of new vinyl-borylene complexes by the hydroboration of alkynes with [(μ3-BH)(Cp*RuCO)2(μ-CO)Fe(CO)3]. Chemistry 2013; 19:2337-43. [PMID: 23293089 DOI: 10.1002/chem.201203627] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Indexed: 11/07/2022]
Abstract
Room temperature photolysis of a triply-bridged borylene complex, [(μ(3)-BH)(Cp*RuCO)(2)(μ-CO)Fe(CO)(3)] (1 a; Cp* = C(5)Me(5)), in the presence of a series of alkynes, 1,2-diphenylethyne, 1-phenyl-1-propyne, and 2-butyne led to the isolation of unprecedented vinyl-borylene complexes (Z)-[(Cp*RuCO)(2)(μ-CO)B(CR)(CHR')] (2: R, R' = Ph; 3: R = Me, R' = Ph; 4: R, R' = Me). This reaction permits a hydroboration of alkyne through an anti-Markovnikov addition. In stark contrast, in the presence of phenylacetylene, a metallacarborane, closo-[1,2-(Cp*Ru)(2)(μ-CO)(2){Fe(2)(CO)(5)}-4-Ph-4,5-C(2)BH(2)] (5 a), is formed. A plausible mechanism has been proposed for the formation of vinyl-borylene complexes, which is supported by density functional theory (DFT) methods. Furthermore, the calculated (11)B NMR chemical shifts accurately reflect the experimentally measured shifts. All the new compounds have been characterized in solution by mass spectrometry and IR, (1)H, (11)B, and (13)C NMR spectroscopies and the structural types were unequivocally established by crystallographic analysis of 2, 5 a, and 5 b.
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A fine tuning of metallaborane to bridged-boryl complex, [(Cp*Ru)2(μ-H)(μ-CO)(μ-Bcat)] (cat = 1,2-O2C6H4; Cp* = η5-C5Me5). Dalton Trans 2013; 42:12828-31. [DOI: 10.1039/c3dt51138c] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Synthesis and Structure of Dirhodium Analogue of Octaborane-12 and Decaborane-14. Inorg Chem 2012; 51:10715-22. [DOI: 10.1021/ic301070e] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Synthesis and Structural Characterization of New Divanada- and Diniobaboranes Containing Chalcogen Atoms. Chemistry 2012; 18:9983-91. [DOI: 10.1002/chem.201200189] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Indexed: 11/09/2022]
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Thyroid function in children with nephrotic syndrome. Mymensingh Med J 2011; 20:407-411. [PMID: 21804503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This study was done to find out the thyroid function of nephrotic children during nephrosis and to compare any significant changes of thyroid function status during nephrosis and remission. This is an observational study with prospective follow up of study subjects. It was carried out over a period of one year from July'2006 to June'2007 in the department of Paediatric Nephrology, National Institute of Kidney Diseases & Urology (NIKDU), Dhaka, Bangladesh. A total of 85 nephrotic children with initial attack and relapse cases were studied. Age ranged from 2-12 years, M: F=1.7:1. All patients were clinically euthyroid. The mean value of serum T3 (0.65±0.31 ng/ml) and T4 (5.04±4.18 μg/ml) in 85 nephrotic children during nephrosis were within normal limit. But the mean value of thyroid stimulating hormone (TSH) was higher than normal level (7.1±5.8 MIU). In 21 nephrotic children thyroid function status was compared during nephrosis and 4 weeks later after achieving remission. A significant increase in TSH level during nephrosis (9.11±6.36 vs. 4.2±3.6 MIU/L, p = 0.005) was found, which normalized during remission. No significant difference between T3 and T4 level was observed. There was a negative correlation of serum albumin with serum TSH level (r = -0.216, p = 0.047). This result suggests that children with nephrotic syndrome commonly have a state of mild or subclinical hypothyroidism during proteinuria although they are clinically euthyroid. This temporary hypothyroid state improves with remission and needs no treatment.
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