A. M. Sargeson, Pure Apll, Chem. 56, 1603, 1984. S. Ahrland, J. Chatt, and N. R.
ID: 478175 • Letter: A
Question
A. M. Sargeson, Pure Apll, Chem. 56, 1603, 1984. S. Ahrland, J. Chatt, and N. R. Davies, Chem Soc. Revs. 12, 265. 1958. C. E. Housecroft and A. G. Sharpe, Imorganic Chemistry. Pearson, Edinburgh, 2005. Chaps, 19-20. A. D. Hunter, V. Mozol, and S. D. Tsal, Organometallics 21, 4578, 2002; S. Y. Lin, M. M, C. Lo, and G. C. Fu. Angew. Chem Int. Ed. 41, 174, 2002. G. J. Kubas, metal Dihydrogen and sigma - Rond Complexes, Kluwer/Plenum, New York, 2001; R. H. Crabtree, Angew. Chem. Int. Ed 32, 789, 1993. S. Geftakis and G. E. Ball, J. Am Chem. Soc., 120, 9953, 1998, C. Hall and R. N. Penitz, Chem Rev. 96. 3125, 1996; D. W. Lee and C. M. Jensen. J. A. Chem. Soc. 118, 8749, 1996. (a) N, Q. Mendez. J. W. Seyler, A. M. Serif, and J. A. Gladysz. J. Am. Chem. Soc. 115, 2323, 1993; (b) T. S. Peng and J. A. Gladysz. J. Am. Chem Soc. 114, 4174, 1992. H. Taube, Pure Appl. Chem. 63, 651, 1991. How many isomers would you expect for a complex with the empirical formula Pt(NH_3)_2Cl_2? Predict the structure of [Me_3Pr(mu_3 - 1)]_4. The arrangement of the Pt and 1 atoms is often considered to be analogous to that of the vertices in one of the Pythagorean regular solids; which one do you think it is? Consider the two complexes MeTiCl_3 and (CO)_5 W(thf). predict the order of reactivity in each case toward the following sets of ligands: NMe_3 PMe_3, CO. How could you distinguish between a square planar and a tetrahedral structure in a nickel(II) complex of which have a pure sample, without using crystallography? You have a set of different ligands of the PR_3 type and a large supply of (CO)_5 W(thf) with which to make a series of complexes (CO)_5 W(PR_3). How could you estimate the relative ordering of the electron-donor power of the different PR_3 ligands?Explanation / Answer
5)
Order of reactivity for MeTiCl3
NMe3 > PMe3 > CO
Ti is in this case d0. So the electron density at the metal atom is low.
NMe3 is a good electron (sigma) donor due to its electronegativity. Because its electronegativity is higher it's better than PMe3. CO gives very stable complexes through (pi )back bonding. Because we have Ti (IV) this does not work effectively.
Order of reactivity for (CO)5 W (thf)-
CO > PMe3 > NMe3
W is d6. So the electron density is high and (pi) back bonding is well established. The most stable complex will be with CO. The binding atom of PMe3 is more polarizable than the N of NMe3. So W(0) is more soft the combination with PMe3 will result to the more stable complex.