The chemistry of early transition elements (Ti, V, Mo, W) with the macrocyclic ligands C(,22)H(,24)N(,4) and H(,2)TPP (tetraphenylporphyrin) has been demonstrated to be more versatile than the exhaustively studied macrocyclic complexes of transition metal from the right hand side of the periodic table. / New (mu)-oxo bridged heterobinuclear dimer complexes have been obtained from the reaction of titanyl and vanadyl species with other metal complexes. The V=O group of VO(C(,22)H(,22)N(,4)) reacts with highly oxophilic Lewis acids such as B(C(,6)H(,5))(,3) and -Si(CH(,3))(,3) yielding (mu)-oxo heterobinuclear compounds (C(,22)H(,22)N(,4))V=O-B(C(,6)H(,5))(,3) and C(,22)H(,22)N(,4)) V-O-Si(CH(,3))(,3) ('+). The Ti=O bond of Ti(O)(C(,22)H(,22)N(,4)) is much more reactive than the V=O group, it forms donor-acceptor complexes with a variety of metal complexes to give (mu)-oxo bridged heterobinuclear complexes of the type, (C(,22)H(,22)N(,4))Ti-O-M'L(M'=Fe('2+), Fe('3+), V('3+), Mn('2+), Cr('3+), Sn('4), MO(DEGREES), L = salen, TPP('2-), CO). The IR spectra and crystal structures indicate that Ti-O bond largely retains its double character. / Mo(CO)(,6) reacts with H(,2)TPP to yield a molybdenum-molybdenum quadruply bonded dimer complex. This discovery, in essence, corrects a fifteen year old literature report, which originally reported the synthesis of Mo(O)(OH)(TPP). The crystal structure shows the geometry of Mo(,2)N(,8) is nominally eclipsed with a twist angle of 18(DEGREES). The temperature dependent ('1)H NMR spectra show two distinguishable species at -95(DEGREES)C as result of minimum rotation of the Mo-Mo (delta) bonding. The activation barrier to rotation was estimated to be 6.3 kcal/mol from NMR line shape analysis. / W(V) porphyrin complexes react with H(,2)O(,2) yielding an unusual tungsten (VI) porphyrin complex having oxo and peroxo groups in cis coordination positions. Furthermore these groups are eclipsed with respect to the porphyrin nitrogen atoms. Two quite different W-N bond distances are observed. This non-equivalence of two types of trans bonding with respect to the nitrogen atoms leads to the most warped porphyrin skeleton known to data. W(O)(O(,2))(TPP) undergoes an intramolecular oxidative reaction at room temperature in which it appears that the coordinated peroxide oxygenates and breaks up the porphyrin ligand. / Ti(C(,22)H(,22)N(,4))Cl(,2) reacts with NaC(,5)H(,5) yielding a new type of sandwich complex Ti(C(,22)H(,22)N(,4))(C(,5)H(,5)). It consists of a minicycle (C(,5)H(,5)('1-)) and the tetraazo macrocyclic C(,22)H(,22)N(,4)('2-). / Source: Dissertation Abstracts International, Volume: 47-08, Section: B, page: 3352. / Thesis (Ph.D.)--The Florida State University, 1986.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75931 |
| Contributors | YANG, CHIOU-HERR., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 289 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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