Theoretical investigations of supramolecular chemisorption adducts of volatile small molecules with a trinuclear silver(I) nitrated pyrazolate complex: DFT modeling of dipole-quadrupole interactions

Theoretical investigations of supramolecular chemisorption adducts of volatile small molecules with a trinuclear silver(I) nitrated pyrazolate complex: DFT modeling of dipole-quadrupole interactions Sammer M Tekarli1, [email protected], Vladimir N Nesterov1, Mohammad A Omary1, Rossana Galassi2, Simone Ricci2, Alfredo Burini2. (1) Department of Chemistry, University of North Texas, Denton, Texas 76203, United States, (2) School of Science and Technology, University of Camerino - Via Sant’Agostino, Camerino, Macerata I-62032, Italy A comparative study on the tendency of a new trinuclear silver(I) pyrazolate, namely [N,N-(3,5-dinitro-pyrazolate)Ag]3 (1) and a similar compound known previously, [N,N-(3,5-bis(trifluoromethyl)pyrazolate)Ag]3 (2) to adsorb small volatile molecules was performed. It was found that 1 has a remarkable tendency to form adducts, at room temperature and atmospheric pressure, with acetone, acetylacetone, ammonia, pyridine, acetonitrile, triethylamine, dimethylsulfide, and tetrahydrothiophene while CO, THF, alcohols, and diethyl ether were not adsorbed. On the contrary, 2 did not undergo adsorption of any of the aforementioned volatile molecules. Density Functional Theory (DFT) results (polarizability, electrostatic potential profiles, kinetics and thermodynamics, and positive point charge calculations) are consistent with the chemisorption model, explain the experimental adsorption selectivity for 1, and the lack of similar adsorption by 2 upon proper selection of the density functional. The M06 method in conjunction with CEP-31G basis set provides good agreement with the experimental data both qualitatively and quantitatively compared to B3LYP/CEP-31G. The results suggest that the adsorption of Lewis basic vapors occurs mainly by kinetic effects. The high vs. low binding energies calculated for the adducts of 1 with acetonitrile vs. CO manifest the experimental findings. The findings in this project suggest that this class of quadrupolar macromolecular complexes may exhibit potential for toxic industrial chemical (TIC) removal applications already known for porous organic polymers

Role of Stress Myocardial Scintigraphy in the Evaluation of Incompletely Revascularized Post-PCI Patients

Percutaneous coronary intervention (PCI) is actually the most used method of revascularization. Although complete revascularization remains a desirable goal, it may not be possible or not easy to plan in many patients. Thus, incomplete revascularization might be a preferred treatment strategy in selected patient categories. Stress myocardial scintigraphy, because of its high diagnostic accuracy and prognostic value and its ability to assess location and extent of myocardial ischemia regardless of symptoms as well as to evaluate patients who are unable to exercise or who have uninterpretable electrocardiogram, is of paramount importance for clinical decision making in patients with multivessel disease and incomplete revascularization

Copper (II) metallocycles as anions receptors. Further studies on their synthesis, spectroscopic and spectrometric characterization in solution

Copper (II) metallocycles as anions receptors. Further studies on their synthesis, spectroscopic and spectrometric characterization in solution Rossana Galassia, Camille S. Oumaroua, Alfredo Burinia, Massimiliano Lupacchinia, Stefania Pucciarellib a School of Science and Technology, Università di Camerino, Via Sant’Agostino 1, 62032, Camerino, Italia b School of Biosciences and Biotechnology, University of Camerino, Via Gentile III da Varano, 1, 62032 Camerino, Italy [email protected] Halide-centered hexanuclear, anionic copper (II) pyrazolate complexes [trans-Cu6{(3,5-CF3)2pz}6(OH)6X]-, X= Cl, Br, I can be isolated in a good yield from the redox reaction of the trinuclear copper(I) pyrazolate complex [µ-Cu3{(3,5-CF3)2pz}3] with a halide source such as Ph3PAuCl, [Bu4N]X, X= Cl, Br or I or PPN(NO2) where PPN is bis(triphenylphosphoranylidene)ammonium [1]. We reported in this work a new route for the synthesis of the [trans-Cu6{(3,5-CF3)2pz}6(OH)6X] starting from the neutral 3,5-(CF3)2pzH. The reactions showed lower yields but fast conversion to the corresponding halide centered metallocycles. A water centered metallocycle was obtained too. The nature of the molecule inside the cavity was discussed by IR spectroscopy, X-ray structural data and by determining the rate constant of the water exchange reaction in acetone solution. The mechanism likely involves the formation of pyrazoles self-aggregates by intermolecular hydrogen bonding. From data analysis, we can assume that the cavity is very affine for chloride and bromide but scarcely selective, while is slightly less affine for iodide. [1] A. A. Mohamed, S. Ricci, A. Burini, R. Galassi Inorg. Chem. 2011, 50, 1014-1020

Coinage metals trinuclear metallocycles: old and new aspects of this class of compounds

Coinage metals trinuclear metallocycles: old and new aspects of this class of compounds Galassi R. a, Oumarou C. S. a, Omary A. M. b, Nesterov V. b, Burini A.a aSchool of Science and Technology, Chemistry Division, University of Camerino, Via S. Agostino 1, 62032 Camerino; e-mail: [email protected] b Department of Chemistry, University of North Texas, Denton, 1155 Union Circle, TX 76203, USA; e-mail: [email protected] Azoles such as imidazoles and pyrazoles are optimal bridging ligands to obtain C,N or N,N trinuclear coinage metals metallocycles. Since past decade till now, few worldwide research groups including us have focused their attention to their synthesis and characterization.[1] Moreover, the photophysical properties[2] the extended network of metallophilic bondings in the supramolecular structure and the pi-acid/pi-base chemistry[3] of these compounds directed the research to theoretical studies bringing to a better interpretation of the experimental behaviors.[4] Here we report the synthesis of new coinage metals metallocycles and their spectroscopic characterizations highlighting points of continuity with the previous analogs and new features for new perspective research lines. As in example, the 1-vinylimidazole resembles the acid-base chemistry of the 1-benzylimidazole gold(I) metallocycle, while substitution in position 4,5 of 1-benzylimidazole with electron-withdrawing group, do not allow the formation of metallocycles with the same synthethic route and mononuclear gold(I) derivatives have been obtained. The nature of the heterocycle and of the substituents, in addition to their position in the azolate ligand defines and tunes the properties of the final products. References: 1) Galassi, R.; Burini, A.; Omary-Rawanashed, M., Omary, M. A., Comm. Inorg. Chem. 2014, in submission. 2) Rawashdeh-Omary, M. A.; Omary, M. A.; Fackler Jr, J. P, Galassi R., Pietroni, B. R.; Burini, A. J. Am. Chem. Soc 2001, 123; 9689-9691. 3) Burini, A.;. Fackler Jr, J. P; Galassi R., Grant, T. A.. Omary, M. A; Rawashdeh-Omary, M. A.; Pietroni, B. R.; Staples R. J. J. Am. Chem. Soc., 2000; 11264-11265. 4) Galassi, R.; Ricci, S.; Burini, A.; Macchioni, A; Marmottini, F.; Tekarli, S. M.; Nesterov, N.V.; Omary, M. A. Inorg. Chem. 2013, 52, 14124-14137

Diabetic patient with three-vessel disease and left main involvement. Surgery yes, but not always

AbstractCoronary artery disease (CAD) is known to be the main cause of morbidity and mortality in patients with diabetes mellitus. Although they do not often show typical recognized symptoms, diabetic patients suffer from more extensive CAD and hence higher incidence of multi-vessel CAD than in non-diabetic subjects. Literature has given the strength of evidence in favor of surgical revascularization in diabetic patients with multi-vessel disease. We report the case of a 61-year old active smoker and diabetic man with atypical symptoms and positive treadmill test. The coronary angiography revealed a severe three-vessel disease and distal left main involvement (SYNTAX score=49). As the patient refused to follow heart team indication to undergo coronary bypass grafting, a percutaneous coronary intervention was successfully performed with intra-aortic balloon counterpulsation support and intravascular ultrasound optimization. The mid-term outcome was good

Management of a patient with multiple device replacements and extractions: When the leadless pacemaker is a viable solution

Leadless pacemaker (LPs) is a safe device and the implantation rates of this device is increasing. The device extraction and replacement are today a challenging procedures especially in case of infections, fragile and older patients or in unfavorable venous anatomy; LPs can be a valid alternative strategy in these cases. We report a case of management of a patient with multiple previous device replacements and extractions, with malfunction of transvenous pacemaker and with a fibrous membrane between the walls of the ventricular lead and the superior vena cava (SVC), who underwent a successful LP implantation

Hereditary Transthyretin Amyloidosis: How to Differentiate Carriers and Patients Using Speckle-Tracking Echocardiography

Background: Hereditary transthyretin amyloidosis is a rare disease caused by transthyretin (TTR) gene mutations. The aim of our study was to identify early signs of cardiac involvement in patients with a TTR gene mutation in order to differentiate carriers from patients with neurological or cardiac disease. Methods: A case-control study was carried out on 31 subjects with the TTR mutation. Patients were divided into three groups: 23% with cardiac amyloidosis and polyneuropathy (group A), 42% with only polyneuropathy (group B) and 35% carriers (group C). Speckle-tracking echocardiography (left-ventricular global longitudinal strain-GLS, atrial stiffness) was performed in all patients. The apical/basal longitudinal strain ratio (SAB) and relative apical sparing (RAS) were assessed in all subjects. Results: Analyzing groups C and B, we only found a significant difference in the SAB (p-value 0.001) and RAS (p-value 0.039). These parameters were significantly more impaired in group A compared to group B (SAB p-value 0.008; RAS p-value 0.002). Also, atrial stiffness was significantly impaired in groups A and B compared to group C. Conclusions: Our study suggests the diagnostic role of the SAB and RAS in cardiac amyloidosis. The SAB and RAS showed a gradual increase from carriers to patients with neurological and cardiac diseases. Thus, these parameters, in addition to atrial stiffness, could be used to monitor carriers. More extensive data are needed