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de Petris G, Cartoni A, Cipollini R, Rosi M, Troiani A. Experimental and Theoretical Evidence for HS 4. J Phys Chem A 2009; 113:14420-3. [DOI: 10.1021/jp9036556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Giulia de Petris
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro, 5-00185 Rome, Italy, Dipartimento di Ingegneria Civile ed Ambientale, ISTM-CNR, Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Antonella Cartoni
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro, 5-00185 Rome, Italy, Dipartimento di Ingegneria Civile ed Ambientale, ISTM-CNR, Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Romano Cipollini
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro, 5-00185 Rome, Italy, Dipartimento di Ingegneria Civile ed Ambientale, ISTM-CNR, Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro, 5-00185 Rome, Italy, Dipartimento di Ingegneria Civile ed Ambientale, ISTM-CNR, Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Anna Troiani
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro, 5-00185 Rome, Italy, Dipartimento di Ingegneria Civile ed Ambientale, ISTM-CNR, Università di Perugia, Via Duranti, I-06131, Perugia, Italy
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de Petris G, Cartoni A, Rosi M, Troiani A. The HSSS Radical and the HSSS− Anion. J Phys Chem A 2008; 112:8471-7. [DOI: 10.1021/jp8055637] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Giulia de Petris
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy, and Dipartimento di Ingegneria Civile ed Ambientale—Sezione Tecnologie Chimiche e Materiali per l’Ingegneria, ISTM-CNR—Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Antonella Cartoni
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy, and Dipartimento di Ingegneria Civile ed Ambientale—Sezione Tecnologie Chimiche e Materiali per l’Ingegneria, ISTM-CNR—Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy, and Dipartimento di Ingegneria Civile ed Ambientale—Sezione Tecnologie Chimiche e Materiali per l’Ingegneria, ISTM-CNR—Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Anna Troiani
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy, and Dipartimento di Ingegneria Civile ed Ambientale—Sezione Tecnologie Chimiche e Materiali per l’Ingegneria, ISTM-CNR—Università di Perugia, Via Duranti, I-06131, Perugia, Italy
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Steudel Y, Wong MW, Steudel R. Electrophilic Attack on Sulfur-Sulfur Bonds: Coordination of Lithium Cations to Sulfur-Rich Molecules Studied by Ab Initio MO Methods. Chemistry 2005; 11:1281-93. [PMID: 15627950 DOI: 10.1002/chem.200400852] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Complex formation between gaseous Li+ ions and sulfur-containing neutral ligands, such as H2S, Me2Sn (n = 1-5; Me = CH3) and various isomers of hexasulfur (S6), has been studied by ab initio MO calculations at the G3X(MP2) level of theory. Generally, the formation of LiS(n) heterocycles and clusters is preferred in these reactions. The binding energies of the cation in the 29 complexes investigated range from -88 kJ mol(-1) for [H2SLi]+ to -189 kJ mol(-1) for the most stable isomer of [Me2S5Li]+ which contains three-coordinate Li+. Of the various S6 ligands (chair, boat, prism, branched ring, and triplet chain structures), two isomeric complexes containing the S5==S ligand have the highest binding energies (-163+/-1 kJ mol(-1)). However, the global minimum structure of [LiS6]+ is of C(3v) symmetry with the six-membered S(6) homocycle in the well-known chair conformation and three Li--S bonds with a length of 256 pm (binding energy: -134 kJ mol(-1)). Relatively unstable isomers of S6 are stabilized by complex formation with Li+. The interaction between the cation and the S6 ligands is mainly attributed to ion-dipole attraction with a little charge transfer, except in cations containing the six sulfur atoms in the form of separated neutral S2, S3, or S4 units, as in [Li(S3)2]+ and [Li(S2)(S4)]+. In the two most stable isomers of the [LiS6]+ complexes, the number of S--S bonds is at maximum and the coordination number of Li+ is either 3 or 4. A topological analysis of all investigated complexes revealed that the Li--S bonds of lengths below 280 pm are characterized by a maximum electron-density path and closed-shell interaction.
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Affiliation(s)
- Yana Steudel
- Institut für Chemie, Technische Universität Berlin, Sekr. C2, 10623 Berlin, Germany.
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Wesemann A, Ahrens H, Förster S, Helm CA. Formation of large PEE domains in PEE212-PEO112 diblock copolymer monolayers: shift of the PEO-desorption transition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:11528-11535. [PMID: 15595780 DOI: 10.1021/la048156q] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
PEE212-PEO112 diblock copolymer monolayers are studied at the air/water interface. At large molecular areas, with X-ray reflectivity, PEE domains are observed, which are partly immersed into the water. The domain thickness increases on compression (28 to 40 A). With off-specular X-ray reflectivity, an average domain radius of 750 A is found, but there are also smaller domains. Due to these space constraints, most PEO blocks form a brush beneath the PEE domains. Only a few PEO blocks form a corona surrounding the domains and adsorb flatly onto the air/water interface. The PEO desorption transition is observed at the typical pressure of 9 mN/m, when the flatly adsorbed PEO is compressed at a domain fraction of 95%. It occurs at 6 A2/EO monomer, about half the value found for lipopolymers or diblock copolymers with NPEE approximately NPEO or NPEE < NPEO. Apparently, the thickness of the PEE domains is determined by the forces from the two interfaces, not by the PEO block, for which flat adsorption beneath the domain would be more favorable instead of formation of a PEO brush.
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Affiliation(s)
- Alexander Wesemann
- Institut für Physik, Ernst-Moritz-Arndt Universität, Friedrich-Ludwig-Jahn-Strasse 16, D-17487 Greifswald, Germany
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