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

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

Bioactive compounds and antioxidant characterization of three edible wild plants traditionally consumed in the Umbria Region (Central Italy): <i>Bunias erucago</i> L. (corn rocket), Lactuca perennis L. (mountain lettuce) and Papaver rhoeas L. (poppy)

The leaves of three edible wild plants, Bunias erucago L. (Corn rocket), Lactuca perennis L. (Mountain lettuce) and Papaver rhoaes L. (Poppy) were analysed for their proximate composition, some nutraceutical components and total antioxidant capacity. The protein levels ranged from 2.7 to 4.1 g/100 g of the edible portion. The range of dietary fibre content was 3.8 to 6.4 g/100 g of the edible portion. The amount of ash, carbohydrate and lipid ranged from 1.7 to 1.9, 3.3 to 4.4 and 0.22to 0.45 g/100 g of the edible portion, respectively. Lipids consisted mainly of polyunsaturated fatty acids with the highest value for the Bunias erucago L. (71.8 % of total fatty acids) and Lactuca perennis L. (70.0 %). Potassium (374.0-521.0 mg/100 g) and calcium (204.8-331.8 mg/100 g) were the most representative macro-elements in the species studied. The values of vitamin E, b-carotene and total vitamin C are included in the range from 0.91 to 2.61 mg/100 g, from 1,957 to 2,631 mg/100 g and from 19.2 to 31.0 mg/100 g, respectively. Our results showed that the total antioxidant capacity performed by the Oxygen Radical Absorbance Capacity (ORAC) method, which ranges from 27.2 to 63.7 μmol TE/g, is highly justifiable by the high content of phenolic compounds (159-246 mg GAE/100 g)

Cupriphication of gold to sensitize d10–d10 metal–metal bonds and near-unity phosphorescence quantum yields

Outer-shell s0/p0 orbital mixing with d10 orbitals and symmetry reductionuponcupriphicationofcyclic trinucleartrigonal-planargold(I) complexes are found to sensitize ground-state Cu(I)–Au(I) covalent bonds and near-unity phosphorescence quantum yields. Heterobimetallic Au4Cu2 {[Au4(μ-C2,N3-EtIm)4Cu2(μ-3,5-(CF3)2Pz)2], (4a)}, Au2Cu {[Au2(μ-C2,N3-BzIm)2Cu(μ-3,5-(CF3)2Pz)], (1) and [Au2(μ-C2, N3-MeIm)2Cu(μ-3,5-(CF3)2Pz)], (3a)}, AuCu2 {[Au(μ-C2,N3-MeIm)Cu2(μ3,5-(CF3)2Pz)2], (3b) and [Au(μ-C2,N3-EtIm)Cu2(μ-3,5-(CF3)2Pz)2], (4b)} and stacked Au3/Cu3 {[Au(μ-C2,N3-BzIm)]3[Cu(μ-3,5-(CF3)2Pz)]3, (2)} formuponreactingAu3 {[Au(μ-C2,N3-(N-R)Im)]3 ((N-R)Im = imidazolate; R =benzyl/methyl/ethyl =BzIm/MeIm/EtIm)} with Cu3 {[Cu(μ-3,5(CF3)2Pz)]3 (3,5-(CF3)2Pz = 3,5-bis(trifluoromethyl)pyrazolate)}. The crystal structures of 1 and 3a reveal stair-step infinite chains whereby adjacent dimer-of-trimer units are noncovalently packed via twoAu(I)⋯Cu(I)metallophilicinteractions,whereas 4a exhibitsa hexanuclear cluster structure wherein two monomer-of-trimer units are linked by a genuine d10–d10 polar-covalent bond with ligandunassisted Cu(I)–Au(I) distances of 2.8750(8) Å each—the shortest such an intermolecular distance ever reported between any two d10 centers so as to deem it a “metal–metal bond” vis-à-vis “metallophilic interaction.” Density-functional calculations estimate 35– 43kcal/molbindingenergy,akintotypicalM–Msingle-bondenergies. Congruently, FTIR spectra of4a showmultiple far-IR bands within 65– 200 cm−1, assignable to vCu-Au as validated by both the Harvey–Gray method of crystallographic-distance-to-force-constant correlation and dispersive density functional theory computations. Notably, the heterobimetallic complexes herein exhibit photophysical properties that are favorable to those for their homometallic congeners, due to threefold-to-twofold symmetry reduction, resulting in cuprophilicsensitizationinextinctioncoefficientandsolid-state photoluminescence quantum yields approaching unity (ΦPL = 0.90–0.97 vs. 0–0.83 for Au3 and Cu3 precursors), which bodes well for potential future utilization in inorganic and/or organic LED applications

Synthesis and crystal structure determination of the bicyclic [bis(μ -P,N-1-benzyl-2-imidazolyl-diphenylphosphine)(μ -O,O'-diperchlorate)dimercury(II)][diperchlorate].

In the attempt to test the oxidizing capability of group 12 perchlorate salts in the regards of phosphane ligands, the 1:1 molar ratio reactions between a donor P, N phosphane ligand (1-benzyl-2-imidazolyl-diphenylphosphine, L) and the respective salts have been performed. In all the cases no ligand oxidation was observed while the metal complexation was highlighted. The species L2M2(ClO4)4 was formed with an increasing predominance from Cd<Zn<Hg. The complex L3M(ClO4)2 was the only solid product isolated in the case of cadmium and the predominant species in solution both for zinc and cadmium reactions. The crystal structure of [bis(μ-P,N-1-benzyl-2-imidazolyl-diphenylphosphine)(μ-O,O’-diperchlorate)dimercury(II)][diperchlorate] shows two centrosymmetric Hg atoms as a part of an eight member cycle formed by two bridging (Bzim)Ph2P ligands coordinated in a head-to-tail mode with P and N as donor atoms. Each Hg atom interacts with the oxygen atoms of two symmetry related molecules of ClO4- that bridge the metal centres forming a second eight member cycle, roughly normal to the first one

Bioinspired Ion Recognition in Hexanuclear Copper Pyrazolate Metallacycles

The chemistry of anion-encapsulation assemblies in copper pyrazolates is reminiscent of the work on the halide- and chalcogenide-centered cubic copper(I) dithiolates. Great efforts have been made to determine the relationship between the design of the ligands, reaction conditions, and the structure of the metallacycles. Fine-tuning the substituent on the pyrazole ligand and controlling the reaction stoichiometry has led to the synthesis of cages, crowns, and anticrowns.These metallacycles are composed of six copper atoms interlinked by the same number of pyrazolate ligands and encapsulate an anion in the cavity

Reactios of trimeric 1-benzyl-2-gold(I)imidazole leading to Au(I) carbene complexes. Crystal structure of [1-benzyl-3-benzoyl-imidazolin-2-yliden]chlorogold(I)

Synthesis and characterization of Au(I) carbene complexes. Crystal structure of [1-benzyl-3-benzoyl-imidazolin-2-yliden]chlorogold(I

Reactions of C-imidazolyllithium derivatives with group Ib compounds: tris[m-(1-alkylimidazolato-N3,C2)tri-gold(I) and -silver(I). Crystal structure of bis(1-benzylimidazolin-2-yliden)gold(I)chloride.

Synthesis and characterization of tris[m-(1-alkylimidazolato-N3,C2)tri-gold(I) and -silver(I). Crystal structure of bis(1-benzylimidazolin-2-yliden)gold(I)chloride