Chelating Agents of a New Generation as an Alternative
... Europe and less than 800 tons in Japan. The demand for phosphonates grows steadily at 3% annually. Besides DTPPH (diethylenetriaminepenta(methylenephosphonic acid)) and NTMP (nitrilotris(methylenephosphonic acid)), HEDP (1-hydroxyethane-1,1-diphosphonic acid) is the most important in this group. HED ...
... Europe and less than 800 tons in Japan. The demand for phosphonates grows steadily at 3% annually. Besides DTPPH (diethylenetriaminepenta(methylenephosphonic acid)) and NTMP (nitrilotris(methylenephosphonic acid)), HEDP (1-hydroxyethane-1,1-diphosphonic acid) is the most important in this group. HED ...
Effect of the ribose versus 2`-deoxyribose residue on the
... for metabolic processes, e.g. in the synthesis of nucleic acids. Hence, it is surprising to find that no detailed comparison is available of the metal ion-binding properties between nucleoside 5’-phosphates and 2’-deoxynucleoside 5’-phosphates. Therefore, we have measured here by potentiometric pH t ...
... for metabolic processes, e.g. in the synthesis of nucleic acids. Hence, it is surprising to find that no detailed comparison is available of the metal ion-binding properties between nucleoside 5’-phosphates and 2’-deoxynucleoside 5’-phosphates. Therefore, we have measured here by potentiometric pH t ...
Transition metals 2
... It must be acidified with dilute sulphuric acid as MnO4¯ is powerful enough to oxidise the chloride ions in hydrochloric acid. It is used to estimate iron(II), hydrogen peroxide, ethanedioic (oxalic) acid and ethanedioate (oxalate) ions. The last two titrations are carried out above 60°C due to the ...
... It must be acidified with dilute sulphuric acid as MnO4¯ is powerful enough to oxidise the chloride ions in hydrochloric acid. It is used to estimate iron(II), hydrogen peroxide, ethanedioic (oxalic) acid and ethanedioate (oxalate) ions. The last two titrations are carried out above 60°C due to the ...
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... powerful and efficient synthetic method for carbon–carbon bond formation leading to carbo- and heterocycles.1 Many useful transformations have been reported for industrial applications as well as for the synthesis of complex molecules. Today, there are several examples of early transition metal comp ...
... powerful and efficient synthetic method for carbon–carbon bond formation leading to carbo- and heterocycles.1 Many useful transformations have been reported for industrial applications as well as for the synthesis of complex molecules. Today, there are several examples of early transition metal comp ...
NO bond in a Ruthenium nitrosyl complex
... mode of action of ruthenium anti-cancer drugs. Furthermore, NO is a well-known non-innocent ligand in coordination chemistry,7 which leads to an intricate and ambiguous electronic structure of the transition metal nitrosyls. NO can attach to the metal both in a linear or a bent configuration, depend ...
... mode of action of ruthenium anti-cancer drugs. Furthermore, NO is a well-known non-innocent ligand in coordination chemistry,7 which leads to an intricate and ambiguous electronic structure of the transition metal nitrosyls. NO can attach to the metal both in a linear or a bent configuration, depend ...
Unsaturated Molecules Containing Main Group Metals
... All the compounds that contain lower valent metals and are monomeric are also colored; the heavier the metal atom, the further the light absorption is shifted to the red (14a is yellow, 14b red, 14c dark red). Dimerization is accompanied by a marked change in color; molten 14b (containing only monom ...
... All the compounds that contain lower valent metals and are monomeric are also colored; the heavier the metal atom, the further the light absorption is shifted to the red (14a is yellow, 14b red, 14c dark red). Dimerization is accompanied by a marked change in color; molten 14b (containing only monom ...
- Zurich Open Repository and Archive
... four ways that metal ions bind to RNA:78,79 (1) Nonspecific charge-screening ions. Before nucleic acid macromolecules can collapse into a discreet structural form, the charge on the polyanionic backbone must be neutralized. This is accomplished by a "cloud" of monovalent or divalent ions that associ ...
... four ways that metal ions bind to RNA:78,79 (1) Nonspecific charge-screening ions. Before nucleic acid macromolecules can collapse into a discreet structural form, the charge on the polyanionic backbone must be neutralized. This is accomplished by a "cloud" of monovalent or divalent ions that associ ...
Dalton Transactions
... by the non-hybrid BP86. Hence, for reactions in which the making and breaking of cobalt-ligand bonds plays an important role, especially in cases where open-shell intermediates are involved, the use of the BP86 functional is preferred over B3LYP.25 We have previously shown that the use of the BP86 f ...
... by the non-hybrid BP86. Hence, for reactions in which the making and breaking of cobalt-ligand bonds plays an important role, especially in cases where open-shell intermediates are involved, the use of the BP86 functional is preferred over B3LYP.25 We have previously shown that the use of the BP86 f ...
Full text - SG
... solvatochromic behavior of the metal-to ligand charge transfer transitions. Atomic orbital contributions to molecular orbitals can be used very effectively to probe the nature of electronic transitions and determine their charge transfer character. Keywords: Time-dependent density-functional respons ...
... solvatochromic behavior of the metal-to ligand charge transfer transitions. Atomic orbital contributions to molecular orbitals can be used very effectively to probe the nature of electronic transitions and determine their charge transfer character. Keywords: Time-dependent density-functional respons ...
Sam P. de Visser,* Jan-Uwe Rohde,* Yong
... Single crystals of the triflate salt of this highly oxidized complex were obtained at −40 ◦ C, and its structure was established by Xray crystallography (Fig. 3a), which revealed an Fe O distance of 1.646(3) Å [40]. This very short distance is consistent with strong and bonding between the Fe ce ...
... Single crystals of the triflate salt of this highly oxidized complex were obtained at −40 ◦ C, and its structure was established by Xray crystallography (Fig. 3a), which revealed an Fe O distance of 1.646(3) Å [40]. This very short distance is consistent with strong and bonding between the Fe ce ...
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... Oithienothiophenes (OTT) are polycondensed heteroaromatic molecules consisting of three condensed thiophene rings. New interest in compounds of this type arose since dithienothiophenes possess three different types of n-conjugation which play an important role as a spacer and donor1 and these compou ...
... Oithienothiophenes (OTT) are polycondensed heteroaromatic molecules consisting of three condensed thiophene rings. New interest in compounds of this type arose since dithienothiophenes possess three different types of n-conjugation which play an important role as a spacer and donor1 and these compou ...
Higher-Coordinated Molecular Silicon Compounds
... even larger variety of molecular compounds containing higher-coordinated silicon atoms are known. These include neutral, anionic, as well as cationic species with mono-, bi-, and multidentate ligands. The probably best-known representative of this class of species is [SiF6]2, its salts and its acid ...
... even larger variety of molecular compounds containing higher-coordinated silicon atoms are known. These include neutral, anionic, as well as cationic species with mono-, bi-, and multidentate ligands. The probably best-known representative of this class of species is [SiF6]2, its salts and its acid ...
View - The Long Group - University of California, Berkeley
... splits the energies of the d-orbitals as (dxy, dx2–y2) < (dxz, dyz) < dz2, with the (dxz, dyz), and dz2 orbital energies being destabilized by p and s-metal–ligand interactions, respectively. In contrast, the (dxy, dx2–y2) orbitals have d symmetry with respect to the axial ligands and are thus not e ...
... splits the energies of the d-orbitals as (dxy, dx2–y2) < (dxz, dyz) < dz2, with the (dxz, dyz), and dz2 orbital energies being destabilized by p and s-metal–ligand interactions, respectively. In contrast, the (dxy, dx2–y2) orbitals have d symmetry with respect to the axial ligands and are thus not e ...
Design, synthesis and study of coordination complexes for quantum computing
... materials can constitute the required tools for the development and implementation of new technological devices at the nanometric scale. Along these lines, in the last ten years the magnetic properties of coordination clusters have been proposed as an exceptional resource for the future information ...
... materials can constitute the required tools for the development and implementation of new technological devices at the nanometric scale. Along these lines, in the last ten years the magnetic properties of coordination clusters have been proposed as an exceptional resource for the future information ...
Interaction of an extended series of N-substituted di(2
... compounds show Curie-Weiss behaviour, with the data indicating weak antiferromagnetic interaction between the pairs of copper ions in each complex. Liquid–liquid (H2 O/CHCl3 ) extraction experiments involving 1–3 and 7–9 as extractants showed that, relative to the parent (unsubstituted) dipic ligand ...
... compounds show Curie-Weiss behaviour, with the data indicating weak antiferromagnetic interaction between the pairs of copper ions in each complex. Liquid–liquid (H2 O/CHCl3 ) extraction experiments involving 1–3 and 7–9 as extractants showed that, relative to the parent (unsubstituted) dipic ligand ...
6149.pdf
... into metal cations. The contents of the extractor are washed with distilled water and analysed for metal by ICP-AES. 2.4. Procedure adopted for complexation/direct in situ complexation When complex formation is performed starting from nitrate, it is called complexation. When complexation is carried ...
... into metal cations. The contents of the extractor are washed with distilled water and analysed for metal by ICP-AES. 2.4. Procedure adopted for complexation/direct in situ complexation When complex formation is performed starting from nitrate, it is called complexation. When complexation is carried ...
Coordination Chemistry Reviews Metal catalysts for the vinyl
... Thus, they can be applied as a glass substitute in lenses, prisms, carrier plates and foils for optical data storage, video and compact discs. They are envisioned as cover and focusing plates for solar cells or in glass fiber optics [58]. The norbornene/ethene copolymer features a high glass-transiti ...
... Thus, they can be applied as a glass substitute in lenses, prisms, carrier plates and foils for optical data storage, video and compact discs. They are envisioned as cover and focusing plates for solar cells or in glass fiber optics [58]. The norbornene/ethene copolymer features a high glass-transiti ...
Interactions of Metal− Metal-Bonded Antitumor Active Complexes
... lines comparable to Rh2(µ-O2CCH3)4.22 The compound cisRh2(DTolF)2(O2CCF3)2(H2O)2 (Chart 1, structure e; DTolF) N,N′-p-tolylformamidinate) with two robust formamidinate and two labile trifluoroacetate bridging groups represents a favorable compromise between antitumor activity and toxic side effects. ...
... lines comparable to Rh2(µ-O2CCH3)4.22 The compound cisRh2(DTolF)2(O2CCF3)2(H2O)2 (Chart 1, structure e; DTolF) N,N′-p-tolylformamidinate) with two robust formamidinate and two labile trifluoroacetate bridging groups represents a favorable compromise between antitumor activity and toxic side effects. ...
and Nickel(II) Chlorides
... 2] and acrylamide based ligands [3⫺5] with transition metals are of interest due to the biological relevance of the amide group in peptides and proteins and their functions as models of metalloproteins active sites. The coordination chemistry of acrylamide has been reviewed with regard to recent pub ...
... 2] and acrylamide based ligands [3⫺5] with transition metals are of interest due to the biological relevance of the amide group in peptides and proteins and their functions as models of metalloproteins active sites. The coordination chemistry of acrylamide has been reviewed with regard to recent pub ...
Intermetal Oxygen, Sulfur, Selenium, and Nitrogen Atom Transfer
... to discussions involving water as a bridging species. 28 Oxygen atom transfer processes generally involve terminal metal oxo complexes as the oxidant. The terminal oxo ligand is typically found in complexes in which the metal exists in a high formal oxidation state (~4+) and has four or fewer d elec ...
... to discussions involving water as a bridging species. 28 Oxygen atom transfer processes generally involve terminal metal oxo complexes as the oxidant. The terminal oxo ligand is typically found in complexes in which the metal exists in a high formal oxidation state (~4+) and has four or fewer d elec ...
Coordination Chemistry Reviews Dibenzometallacyclopentadienes
... [NiH(i Pr2 PCH2 )2 ]2 dimer has also been used to achieve C–S bond activation, resulting in Ni(2,2 -bph) complexes in moderate yields, although bph complexes were not the sole reaction products [17]. 2.2. Synthesis by transmetallation A second method for the synthesis of 2,2 -bph complexes involve ...
... [NiH(i Pr2 PCH2 )2 ]2 dimer has also been used to achieve C–S bond activation, resulting in Ni(2,2 -bph) complexes in moderate yields, although bph complexes were not the sole reaction products [17]. 2.2. Synthesis by transmetallation A second method for the synthesis of 2,2 -bph complexes involve ...
1 The Chemistry of Gold - Wiley-VCH
... found and the covalent radius of gold is smaller than that of silver. Schmidbaur has recently confirmed this in the isomorphous di-coordinated complexes [M(PMes3)2]BF4 (M ¼ Ag, Au; Mes ¼ mesithyl) [2]. The estimated covalent radii for silver and gold are 1.33 and 1.25 Å, respectively, so di-coordinat ...
... found and the covalent radius of gold is smaller than that of silver. Schmidbaur has recently confirmed this in the isomorphous di-coordinated complexes [M(PMes3)2]BF4 (M ¼ Ag, Au; Mes ¼ mesithyl) [2]. The estimated covalent radii for silver and gold are 1.33 and 1.25 Å, respectively, so di-coordinat ...
Calculating interaction energies in transition metal complexes with
... the AVTZⴱ calculation on complex 2 only required approximately 60% of the calculation time for AVTZ, with both computations run on the same AMD Opteron 246 based machine兲. Previous investigations have shown that such basis sets also help to minimize the amount of residual HF BSSE in interaction ener ...
... the AVTZⴱ calculation on complex 2 only required approximately 60% of the calculation time for AVTZ, with both computations run on the same AMD Opteron 246 based machine兲. Previous investigations have shown that such basis sets also help to minimize the amount of residual HF BSSE in interaction ener ...
Oxygenation of saturated and unsaturated hydrocarbons with
... active oxidizing species affect product selectivity, stereoselectivity, and regioselectivity of oxidations catalyzed by Mn porphyrins.28,29 Our preliminary ultraviolet studies have confirmed generation of a high-valent oxidizing species by observation of a Soret band at about 420 nm in sodium period ...
... active oxidizing species affect product selectivity, stereoselectivity, and regioselectivity of oxidations catalyzed by Mn porphyrins.28,29 Our preliminary ultraviolet studies have confirmed generation of a high-valent oxidizing species by observation of a Soret band at about 420 nm in sodium period ...
Ligand
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In coordination chemistry, a ligand (/lɪɡənd/) is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from covalent to ionic. Furthermore, the metal-ligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic ""ligand.""Metals and metalloids are bound to ligands in virtually all circumstances, although gaseous ""naked"" metal ions can be generated in high vacuum. Ligands in a complex dictate the reactivity of the central atom, including ligand substitution rates, the reactivity of the ligands themselves, and redox. Ligand selection is a critical consideration in many practical areas, including bioinorganic and medicinal chemistry, homogeneous catalysis, and environmental chemistry.Ligands are classified in many ways like : their charge, their size (bulk), the identity of the coordinating atom(s), and the number of electrons donated to the metal (denticity or hapticity). The size of a ligand is indicated by its cone angle.