| Summary: | 博士 === 國立中興大學 === 化學系 === 89 === Part I
Abstract
The new compound (trifluoromethanesulfonato)(tetrahydrofuran)(meso-tetraphenylporphyrinato)thallium(III) tetrahydrofuran solvate, [Tl(tpp)(OSO2CF3)(THF).THF](1), has been synthesized and its crystal structure determined by X-ray analysis. The coordination sphere of the Tl3+ ion is an distorted octahedron with the triflate and THF in a trans configuration. The average Tl-N bond distance is 2.145(7) Å and the Tl atom is displaced 0.295 Å fro the porphyrin plane. The Tl(1)-O(1) and Tl(1)-O(4) distances are 2.387(6) and 2.778(7) Å, respectively. The triflate CF3SO3- is unidentately coordinated to the Tl atom in solid state. However, the complex Tl(tpp)(OSO2CF3)(THF).THF (1) ionizes completely to Tl(tpp)(THF)+ and ionic CF3SO3- in acetone-d6 or THF-d8. 13C and 19F of the triflate for compound (1) in acetone-d6 at -80 °C observed at d = 121.2 ppm with 1J(C-F) = 321 Hz and d = -78.4 ppm, respectively, definitely prove the existence of ionic CF3SO3- via the dissociation of compound (1).
Part II
Abstract
The crystal structures of acetato N-tosylimido-meso -tetraphenylporphyrinato thallium(III), Tl(N-NTs-tpp)(OAc) (1), and acetato N-tosylimido-meso-tetraphenylporphyrinato gallium(III), Ga(N-NTs-tpp)(OAc) (2), were determined. The coordination sphere around the Tl3+ ion is a distorted square-based pyramid in which the apical site is occupied by a chelating bidentate OAc- group, whereas for Ga3+ ion, it is a distorted trigonal bipyramid with O(3), N(3), and N(5) lying in the equatorial plane. The porphyrin ring in the two complexes is distorted to large extent. For the Tl3+ complex, the pyrrole ring bonded to the NTs ligand lies in a plane with a dihedral angle of 50.8° with respect to the (3N) plane which contains the three pyrrole nitrogens bonded to Tl3+, but for the Ga3+ complex, this angle is found to be only 24.5°. In the former complex, Tl3+ and N(5) are located on the same side at 1.18 and 1.29 Å from its (3N) plane, but in the latter one, Ga3+ and N(5) are located on different sides at -0.15 Å and 1.31 Å from its (3N) plane. The free energy of activation at the coalescence temperature Tc for the intermolecular acetate exchange process in (1) in CD2Cl2 solvent is found to be DG‡171 = 36.0 kJ/mol through 1H NMR temperature-dependent measurements. In the slow-exchange region, the methyl and carbonyl (CO) carbons of the OAc- group in (1) are separately located at d 18.5 [3J(Tl-13C) = 220 Hz] and 176.3 [2J(Tl-13C) = 205 Hz] at -110°C.
Part III
Abstract
The crystal structure of diacetato(N—methyl—meso—tetraphenylporphyrinato)thallium(III), Tl(N—Me—tpp)(OAc)2 (4), was established and the coordination sphere around Tl3+ ion is described as an eight—coordinate square—based antiprism in which two cis chelating bidentate OAc— groups occupy two apical sites. The three pyrrole nitrogen atoms [i.e. N(1), N(3), N(4)] strongly bonded to Tl3+ is adopted as a reference plane 3N. The pyrrole N(2) ring bearing the methyl group [i.e. C(45)H3] is the most deviated one from the 3N plane, making a dihedral angle of 21.4°, whereas smaller angles of 9.1°, 7.1° and 0.9° occur with pyrroles N(1), N(3), and N(4), respectively. Because of its larger size, the thallium (III) ion Tl3+ is considerably out of the 3N plane; its displacement of 1.17 Å is in the same direction as that of the two apical OAc— ligands. The intermolecular acetate exchange process for 4 in THF—d8 solvent is examined through 1H NMR temperature—dependent measurements. In the slow—exchange region, the methyl and carbonyl carbons of the OAc— groups in 4 are separately located at d 18.6 [3J(Tl—13C) = 405 Hz] and 170.8 [2J(Tl—13C) = 334 Hz] at —80°C, respectively.
Part IV
Abstract
Treatment of tetraphenyl-21-thiaporphyrin (StppH) with Hg(OAc)2 in CH2Cl2 yields diamagnetic HgII(Stpp)Cl complex. The coordination sphere around Hg2+ in the monomeric molecule is described as a five-coordinate distorted trigonal bipyramid with the bonding to the three pyrrole nitrogens [Hg(1)-N = 2.104(4), 2.626(4), 2.640(4) Å], the thiophene sulfur [Hg(1)-S = 2.801(1) Å], and one axial choride ligand [Hg(1)-Cl(1) = 2.318(1) Å]. The plane of the three pyrrole nitrogen atoms [i.e., N(1), N(2), N(3)] bonded to Hg2+ is adopted as a reference plane 3N. Because of its larger size, the Hg2+ is considerably out of the 3N plane; its displacement of 1.41 Å is in the same direction as that of the apical Cl- ligand. The thiophene ring is slightly folded so that the dihedral angle between the C(13)-C(14)-C(15)-C(16) and C(13)-S(1)-C(16) planes is 7.3°. Weak intermolecular secondary contacts occur between terminal chlorine and mercury(II) atom [Hg(1)....Cl(1A) = 3.365 Å]. These secondary contacts link the two monomeric molecules into an asymmetrically bridged Hg(1)[m-Cl(1), m-Cl(1A)]Hg(1A) dimeric units. The dimeric cores contain long Hg(1)....Hg(1A) contacts (4.214 Å) with narrow bridging angle [Hg(1)-Cl(1)-Hg(1A) = 93.9°]. Consequently, the mercury(II) shows an effective six-coordination in dimeric molecules and thus possess distorted trigonal prismatic geometry.
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