title: Synthesis of Bis(aliphatic amine)osmium(II), Bis(arylamido)osmium(IV), and Bis(imido)- and Oxo(imido)osmium(VI) Porphyrins.
abstract: The syntheses, characterization, and reactivity of a series of osmium porphyrins, Os(II)(Por)(H(2)NR)(2) [Por = dianions of octaethylporphyrinato (OEP), tetraphenylporphyrinato (TPP), meso-tetrakis(p-tolyl)porphyrinato (TTP), meso-tetrakis(4-chlorophenyl)porphyrinato (4-Cl-TPP), meso-tetrakis(3,4,5-trimethoxyphenyl)porphyrinato (3,4,5-MeO-TPP), R = (t)Bu; Por = TPP, R = (i)Pr], Os(II)(Por)(HNEt(2))(2) (Por = TPP, 3,4,5-MeO-TPP), Os(IV)(Por)(NHAr)(2) (Por = OEP, TPP, 3,4,5-MeO-TPP; Ar = Ph, 4-F-Ph), Os(VI)(Por)(N(t)Bu)(2) (Por = TPP, TTP, 4-Cl-TPP, 3,4,5-MeO-TPP), Os(VI)O(Por)(N(t)Bu) (Por = TPP, TTP, 4-Cl-TPP, 3,4,5-MeO-TPP), and Os(VI)O(Por)(4-F-PhN) (Por = TPP, 3,4,5-MeO-TPP) are described. The complexes Os(Por)(HNAr)(2) are prepared from the reactions of Os(Por)(N(2))(THF) with arylamines in aerobic tetrahydrofuran. Air oxidations of Os(Por)(H(2)N(t)Bu)(2) in tetrahydrofuran and in the presence of H(2)N(t)Bu give OsO(Por)(N(t)Bu) and Os(Por)(N(t)Bu)(2). The X-ray crystal structures of OsO(TTP)(N(t)Bu).EtOH and Os(4-Cl-TPP)(N(t)Bu)(2) have been determined. Crystal data for OsO(TTP)(N(t)Bu).EtOH: monoclinic, space group P2(1)/c, a = 13.546(6) Å, b = 23.180(3) Å, c = 16.817(3) Å, beta = 90.84(2) degrees, V = 5279.7(1.0) Å(3), Z = 4. Os(4-Cl-TPP)(N(t)Bu)(2): monoclinic, space group P2(1)/c, a = 11.046(2) Å, b = 18.380(3) Å, c = 23.640(4) Å, beta = 97.22(1) degrees, V = 4759.8(1.0) Å(3), Z = 4. The Os=O and Os=N(t)Bu distances in OsO(TTP)(N(t)Bu).EtOH are 1.772(7) and 1.759(9) Å, respectively. The Os=N(t)Bu distances in Os(4-Cl-TPP)(N(t)Bu)(2) average 1.775 Å. The imido angles range from 165.8(8) to 170.6(9) degrees. For the infrared spectra of these complexes, a discussion on the "oxidation state marker" band in the vicinity of 1000 cm(-)(1) is presented. The differences in the electronic properties of osmium porphyrins at various oxidation states are also described.
authors.affiliation: Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
authors.forename: Zao-Ying
authors.initials: ZY
authors.lastname: Li
authors.forename: Jie-Sheng
authors.initials: JS
authors.lastname: Huang
authors.forename: Michael Chi-Wang
authors.initials: MC
authors.lastname: Chan
authors.forename: Kung-Kai
authors.initials: KK
authors.lastname: Cheung
authors.forename: Chi-Ming
authors.initials: CM
authors.lastname: Che