Ligand total

An additional concern arises in regard to any differences which may exist between the classical theory and the quantum-mechanical approach in the calculation of the Franck-Condon factors for symmetrical exchange reactions. In fact, the difference is not very large. For a frequency of 400 cm for metal-ligand totally symmetric vibrational modes, one can expect... 

Carbonyl replacement dominates the observed photoreactions of Co complexes, and with CO-like ligands, total substitution is possible. Table 1 lists examples. The complex CofCOjNO is unusual in that the primary photoprocess is a linear to bent NO transformation, followed by an associative displacement of CO from this shortlived intermediate. Photolysis in CHClj leads to incorporation of chloride in the complex if PPhj is present, then Co(PPh3)2Cl2 is formed " if NO is present then [Co(NO)2C1 j is generated Trialkylsilane exchange in RjSiCo(CO) (Table 1) proceeds via oxidative addition of RjSiH to the intermediate formed by CO loss, followed by reductive elimination of R SiH. This is true for surface-confined analogues as well d. 

Metal Carbonyl Number of electrons contributed by metal Number of electrons contributed by ligands Total... 

Complex Oxid. No. of Pt Ligands Total Charge of Ligands Charge of Complex... 

In our simple model, the expression in A2.4.135 corresponds to the activation energy for a redox process in which only the interaction between the central ion and the ligands in the primary solvation shell is considered, and this only in the fonn of the totally synnnetrical vibration. In reality, the rate of the electron transfer reaction is also infiuenced by the motion of molecules in the outer solvation shell, as well as by other... 

In the example, we proceed from the right (rotated molecule) to the left (reference molecule). The first transposition is done with ligands 4 and 2, in order to obtain the fir.st part of the reference. scqttencc 1 2". Then, only a pcrmtttation of ligands 3 and 4 has to be done to obtain the reference matrix on the left-hand side. Thus, in total, we have executed two transpositions (4 2) and (3 4),... 

For Iran sition metals th c splittin g of th c d orbitals in a ligand field is most readily done using HHT. In all other sem i-ctn pirical meth -ods, the orbital energies depend on the electron occupation. HyperCh em s m oiccii lar orbital calcii latiori s give orbital cri ergy spacings that differ from simple crystal field theory prediction s. The total molecular wavcfunction is an antisymmetrized product of the occupied molecular orbitals. The virtual set of orbitals arc the residue of SCT calculations, in that they are deemed least suitable to describe the molecular wavefunction, ... 

Asymmetric cyclization using chiral ligands has been studied. After early attempts[142-144], satisfactory optical yields have been obtained. The hexahy-dropyrrolo[2,3-6]indole 176 has been constructed by the intramolecular Heck reaction and hydroaryiation[145]. The asymmetric cyclization of the enamide 174 using (S j-BINAP affords predominantly (98 2) the ( )-enoxysilane stereoisomer of the oxindole product, hydrolysis of which provides the ( l-oxindole aldehyde 175 in 84% yield and 95% ec. and total synthesis of (-)-physostig-mine (176) has been achieved[146]. 

Carboxylic acids are produced in water. Selection of solvents is crucial and the carbonylation of the enol triflate 480 can be carried out in aqueous DMF, and that of the aryl triflate 481 in aqueous DMSO using dppf as a ligand[328,334]. The carbonylation of the enol triflate 482 to form the a, 0. unsaturated acid 483 using dppf as a ligand in aqueous DMF has been applied in the total synthesis of multifunctionalized glycinueclepin[335]. 

Of the three methods, the method of continuous variations, also called Job s method, is the most popular. In this method a series of solutions is prepared such that the total moles of metal and ligand, tot> in each solution is the same. Thus, if ( m)( and ( l)( are, respectively, the moles of metal and ligand in the i-th solution, then... 

To determine the formula for the complex between Fe + and o-phenanthroline, a series of solutions was prepared in which the total concentration of metal and ligand was held constant at 3.15 X 10 M. The absorbance of each solution was measured at a wavelength of 510 nm. Using the following data, determine the formula for the complex. 

In the slope-ratio method two sets of solutions are prepared. The first set consists of a constant amount of metal and a variable amount of ligand, chosen such that the total concentration of metal, Cm, is much greater than the total concentration of ligand. Cl- Under these conditions we may assume that essentially all the ligand is complexed. The concentration of a metal-ligand complex of the general... 

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