A Stable Five-Coordinate Platinum(IV) Alkyl
... related Pt(II) complex 2 discussed below. In solution, no 195Pt satellites are seen for the 1H NMR signals of the isopropyl hydrogens. Thus, there is no indication of agostic interactions between the isopropyl moieties on the ligand and the metal. It is interesting that the methyl group trans to the ...
... related Pt(II) complex 2 discussed below. In solution, no 195Pt satellites are seen for the 1H NMR signals of the isopropyl hydrogens. Thus, there is no indication of agostic interactions between the isopropyl moieties on the ligand and the metal. It is interesting that the methyl group trans to the ...
Fulltext PDF - Indian Academy of Sciences
... ligands with molybdenum carbonyl derivatives forming complexes of the type, [Mo(CO)3 {η3 -PhN(PX)2 {(-OC6 H2 (t Bu)2 )(μ-S)((t Bu)2 C6 H2 O-)}] (3, X = Cl; 4, X = F). A crystal structure of the fluoro derivative 4 showed the facial tricarbonyl complex comprising of a relatively strain free tetracycl ...
... ligands with molybdenum carbonyl derivatives forming complexes of the type, [Mo(CO)3 {η3 -PhN(PX)2 {(-OC6 H2 (t Bu)2 )(μ-S)((t Bu)2 C6 H2 O-)}] (3, X = Cl; 4, X = F). A crystal structure of the fluoro derivative 4 showed the facial tricarbonyl complex comprising of a relatively strain free tetracycl ...
Mimicking nitrogenase
... is the vicinity of Fe6 and Fe2 (Fig. 1).5,44,45 In conjunction with this, careful and ingenious experimentation at low temperatures with wild type and mutant enzymes has enabled the trapping of species apparently containing bound H, N2 , N2 H2 and N2 H4 , although structural characterisation of thes ...
... is the vicinity of Fe6 and Fe2 (Fig. 1).5,44,45 In conjunction with this, careful and ingenious experimentation at low temperatures with wild type and mutant enzymes has enabled the trapping of species apparently containing bound H, N2 , N2 H2 and N2 H4 , although structural characterisation of thes ...
Potentiometry and NMR studies of 1,5,9
... average value (log K I = 12.8) is quite similar to the first protonation constant of [12]ane-N, (log K1 = 12.616). The protonation constants of DOTRA3- obtained by spectrophotometry and pH potentiometry are shown in Table 11, where the protonation constants of [ 121ane-N,, as well as [9]ane-N3 and N ...
... average value (log K I = 12.8) is quite similar to the first protonation constant of [12]ane-N, (log K1 = 12.616). The protonation constants of DOTRA3- obtained by spectrophotometry and pH potentiometry are shown in Table 11, where the protonation constants of [ 121ane-N,, as well as [9]ane-N3 and N ...
Chapter 6 - VU Research Portal
... interest in order to understand the catalytic activity of these complexes.[307,308] This is an ...
... interest in order to understand the catalytic activity of these complexes.[307,308] This is an ...
Coordination Chemistry Reviews 272 - Didier Astruc`s Library
... century, is now a common heterocyclic ligand in chemistry and biology [1]. Relatively few studies have been reported before the year 2000 due to the limited availability of functional triazole derivatives when the non-selective Huisgens reaction was used for their synthesis [1b,1c]. The breakthrough ...
... century, is now a common heterocyclic ligand in chemistry and biology [1]. Relatively few studies have been reported before the year 2000 due to the limited availability of functional triazole derivatives when the non-selective Huisgens reaction was used for their synthesis [1b,1c]. The breakthrough ...
Lecture 1: Key Concepts in Stereoselective Synthesis
... While frustrated Lewis pairs are not commonly used in asymmetric reductions, nevertheless it is an area, which has been studied more and more and has found applications not only in hydrogenation but also in hydroamination, polymerization catalysis and other fields. 4.1 Definition of frustrated Lewis ...
... While frustrated Lewis pairs are not commonly used in asymmetric reductions, nevertheless it is an area, which has been studied more and more and has found applications not only in hydrogenation but also in hydroamination, polymerization catalysis and other fields. 4.1 Definition of frustrated Lewis ...
Design and synthesis optimization of bis(β
... Although it was useful in determination of the polymerization mechanism, its activity was not satisfactory. In order to find more active species trivalent lanthanum alkoxides Ln(OR)3 (Ln=La, Y; R=i-‐ ...
... Although it was useful in determination of the polymerization mechanism, its activity was not satisfactory. In order to find more active species trivalent lanthanum alkoxides Ln(OR)3 (Ln=La, Y; R=i-‐ ...
Document
... series, the atomic radii actually ____________again. At the beginning of the series, the increase in __________ _______________ with atomic number pulls in the electron cloud, resulting in a reduction of atomic size. Since electrons are added to an inner d subshell across the series, this adds to th ...
... series, the atomic radii actually ____________again. At the beginning of the series, the increase in __________ _______________ with atomic number pulls in the electron cloud, resulting in a reduction of atomic size. Since electrons are added to an inner d subshell across the series, this adds to th ...
1. General introduction 1.1 Organometallic chemistry and homogeneous catalysis
... been used to a lesser extent in the copolymerization of alkenes with carbon monoxide. Monodentate ligands and bidentate ligands with relatively large bite angles are not used to avoid coordination in trans position in mono or bimetallic complexes, respectively.75 Therefore, depending on the alkene i ...
... been used to a lesser extent in the copolymerization of alkenes with carbon monoxide. Monodentate ligands and bidentate ligands with relatively large bite angles are not used to avoid coordination in trans position in mono or bimetallic complexes, respectively.75 Therefore, depending on the alkene i ...
Stabilization and Reactivity of Low Oxidation State Indium Compounds
... The work described herein focuses on the chemistry of low oxidation state indium salts. Indium in its +1 oxidation state is electron rich, as it possesses a “lone pair” of electrons which are capable of undergoing further chemistry, such as oxidative addition and transition metal ligation. One of th ...
... The work described herein focuses on the chemistry of low oxidation state indium salts. Indium in its +1 oxidation state is electron rich, as it possesses a “lone pair” of electrons which are capable of undergoing further chemistry, such as oxidative addition and transition metal ligation. One of th ...
CHAPTER 19 TRANSITION METALS AND COORDINATION
... Sc3+ has no electrons in d orbitals. Ti3+ and V3+ have d electrons present. The color of transition metal complexes results from electron transfer between split d orbitals. If no d electrons are present, no electron transfer can occur, and the compounds are not colored. ...
... Sc3+ has no electrons in d orbitals. Ti3+ and V3+ have d electrons present. The color of transition metal complexes results from electron transfer between split d orbitals. If no d electrons are present, no electron transfer can occur, and the compounds are not colored. ...
Colors Trend: Transition Metal Chemistry
... Transition metals are located in the center of our modern day periodic table. Aside from the ions that are formed, and some of the more common ionic compounds involving species like copper and iron, we have ignored these species all year. The transition elements are remarkably useful in their uncomb ...
... Transition metals are located in the center of our modern day periodic table. Aside from the ions that are formed, and some of the more common ionic compounds involving species like copper and iron, we have ignored these species all year. The transition elements are remarkably useful in their uncomb ...
W(CN)5(CO)2 - Stanford University
... as well as to their diffuse valence d orbitals, which can result in strong magnetic exchange.[3] Owing to poorly understood reactivity patterns and the preference for low-spin electron configurations, however, there are relatively few examples of simple, paramagnetic building units containing these ...
... as well as to their diffuse valence d orbitals, which can result in strong magnetic exchange.[3] Owing to poorly understood reactivity patterns and the preference for low-spin electron configurations, however, there are relatively few examples of simple, paramagnetic building units containing these ...
Fast and efficient molecular electrocatalysts for H 2
... (less than 1 Å) between acidic and basic functional groups followed by rotation and translation of these groups.15–17 Thus the movement of protons involves a continuous pathway from the iron atom to the exterior of the molecule. This observation suggests that similar control may be important for syn ...
... (less than 1 Å) between acidic and basic functional groups followed by rotation and translation of these groups.15–17 Thus the movement of protons involves a continuous pathway from the iron atom to the exterior of the molecule. This observation suggests that similar control may be important for syn ...
Density Functional Study on the Preactivation Scenario of the
... could operate in competition with the reported CO loss would be the insertion of an alkyne ligand into the metal coordination sphere prior to CO elimination (associative mechanism). Such a mechanism is not unknown in the field of transition-metal chemistry; e.g., carbonylmetal complexes with a 17-VE ...
... could operate in competition with the reported CO loss would be the insertion of an alkyne ligand into the metal coordination sphere prior to CO elimination (associative mechanism). Such a mechanism is not unknown in the field of transition-metal chemistry; e.g., carbonylmetal complexes with a 17-VE ...
(PhCECPh) (2) - ACS Publications
... With the metal fragment orbitals in hand, let us consider their interaction with an acetylene. As one might expect, the basic pattern of interaction for 2,3,and 4 is very much alike. A representative one may be that for 4, Mo(porphyrin)(HC=CH), which is given in Figure 2. Since the porphyrin orbital ...
... With the metal fragment orbitals in hand, let us consider their interaction with an acetylene. As one might expect, the basic pattern of interaction for 2,3,and 4 is very much alike. A representative one may be that for 4, Mo(porphyrin)(HC=CH), which is given in Figure 2. Since the porphyrin orbital ...
What Should Be Impossible: Resolution of the Mononuclear Gallium
... few resolved chiral complexes of labile metals have been reporteds they should be impossible. The d10 Ga3+ ion has no ligand field stabilization and is consequently considered a classic example of a “labile” metal ion. We report here the resolution of simple complexes of this cation. The hydroxamate ...
... few resolved chiral complexes of labile metals have been reporteds they should be impossible. The d10 Ga3+ ion has no ligand field stabilization and is consequently considered a classic example of a “labile” metal ion. We report here the resolution of simple complexes of this cation. The hydroxamate ...
Chapter 1: General Introduction
... relevance. Under these circumstances the bond between the metal atom and carbon atom is longer, and one would not necessarily draw the bond as containing double bond character. This is the case with N–heterocyclic carbene ligands (NHCs), which are quite stable as free uncomplexed molecules6 – they a ...
... relevance. Under these circumstances the bond between the metal atom and carbon atom is longer, and one would not necessarily draw the bond as containing double bond character. This is the case with N–heterocyclic carbene ligands (NHCs), which are quite stable as free uncomplexed molecules6 – they a ...
Coordination Complexes Involving Electroactive
... functionalized TTF ligands [Co2M(PhCOO)6(L7)2] M(II) = Mn (15) and Co (16). The Co(II) and M(II) (Mn and Co) ions are in blue and black respectively. (b) Thermal variation of the magnetic susceptibility of 15. Compound 16 displays a room temperature MT value of 8.56 cm3 K mol-1 giving a calculated ...
... functionalized TTF ligands [Co2M(PhCOO)6(L7)2] M(II) = Mn (15) and Co (16). The Co(II) and M(II) (Mn and Co) ions are in blue and black respectively. (b) Thermal variation of the magnetic susceptibility of 15. Compound 16 displays a room temperature MT value of 8.56 cm3 K mol-1 giving a calculated ...
Aquatic Geochemistry
... Aquatic Geochemistry - Complexation Ions in solution often associate with other ions, forming complexes. This affects the solubility and reactivity of ions. For example, if ions form stable, soluble complexes, this greatly enhances the solubility of the ions. Central ion (metal) - ligands (ions or ...
... Aquatic Geochemistry - Complexation Ions in solution often associate with other ions, forming complexes. This affects the solubility and reactivity of ions. For example, if ions form stable, soluble complexes, this greatly enhances the solubility of the ions. Central ion (metal) - ligands (ions or ...
Pdf - Text of NPTEL IIT Video Lectures
... So, iron if it is there and particularly when it is forming certain complexes with the ligand, it is forming the corresponding low spin compound. So, low spin iron compound is forming over there and in octahedral geometry, it will have the corresponding electronic configuration of t 2 g 5 and that t ...
... So, iron if it is there and particularly when it is forming certain complexes with the ligand, it is forming the corresponding low spin compound. So, low spin iron compound is forming over there and in octahedral geometry, it will have the corresponding electronic configuration of t 2 g 5 and that t ...
Handout-5
... where ε is the molar extinction coefficient ( in L cm-1 mole-1 ), c is concentration in mole L-1 and l is the path length in cm. A is known as ‘Absorbance’ and it is dimensionless. To explain the absorption spectra of coordination complexes, it is necessary to know the selection rules that govern el ...
... where ε is the molar extinction coefficient ( in L cm-1 mole-1 ), c is concentration in mole L-1 and l is the path length in cm. A is known as ‘Absorbance’ and it is dimensionless. To explain the absorption spectra of coordination complexes, it is necessary to know the selection rules that govern el ...
Ligand
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.