65814-72-4Relevant academic research and scientific papers
Stable group 8 metal porphyrin mono- And bis(dialkylcarbene) complexes: Synthesis, characterization, and catalytic activity
Che, Chi-Ming,Huang, Jie-Sheng,Low, Kam-Hung,Wan, Qingyun,Wang, Hai-Xu,Zhang, Jun-Long,Zhou, Cong-Ying
, p. 2243 - 2259 (2020/03/11)
Alkyl-substituted carbene (CHR or CR2, R = alkyl) complexes have been extensively studied for alkylcarbene (CHR) ligands coordinated with high-valent early transition metal ions (a.k.a. Schrock carbenes or alkylidenes), yet dialkylcarbene (CR2) complexes remain less developed with bis(dialkylcarbene) species being little (if at all) explored. Herein, several group 8 metal porphyrin dialkylcarbene complexes, including Fe- and Ru-mono(dialkylcarbene) complexes [M(Por)(Ad)] (1a,b, M = Fe, Por = porphyrinato dianion, Ad = 2-adamantylidene; 2a,b, M = Ru) and Os-bis(dialkylcarbene) complexes [Os(Por)(Ad)2] (3a-c), are synthesized and crystallographically characterized. Detailed investigations into their electronic structures reveal that these complexes are formally low-valent M(ii)-carbene in nature. These complexes display remarkable thermal stability and chemical inertness, which are rationalized by a synergistic effect of strong metal-carbene covalency, hyperconjugation, and a rigid diamondoid carbene skeleton. Various spectroscopic techniques and DFT calculations suggest that the dialkylcarbene Ad ligand is unique compared to other common carbene ligands as it acts as both a potent σ-donor and π-acceptor; its unique electronic and structural features, together with the steric effect of the porphyrin macrocycle, make its Fe porphyrin complex 1a an active and robust catalyst for intermolecular diarylcarbene transfer reactions including cyclopropanation (up to 90% yield) and X-H (X = S, N, O, C) insertion (up to 99% yield) reactions.
Synthesis of Bis(aliphatic amine)osmium(II), Bis(arylamido)osmium(IV), and Bis(imido)and Oxo(imido)osmium(VI) Porphyrins
Li, Zao-Ying,Huang, Jie-Sheng,Chan, Michael Chi-Wang,Cheung, Kung-Kai,Che, Chi-Ming
, p. 3064 - 3071 (2008/10/09)
The syntheses, characterization, and reactivity of a series of osmium porphyrins, OsII(Por)(H2NR)2 [Por = dianions of octaethylporphyrinato (OEP), tetraphenylporphyrinato (TPP), meso-tetrakis(p-tolyl)porphyrinato (TTP), mesotetrakis(4-chlorophenyl)porphyrinato (4-Cl-TPP), meso-tetrakis(3,4,5-trimethoxyphenyl)porphyrinato (3,4,5-MeO-TPP). R = tBu; Por = TPP, R = iPr], OsII(Por)(HNEt2)2 (Por = TPP, 3,4,5-MeO-TPP), OsIV(Por)(NHAr)2 (Por = OEP, TPP, 3,4,5-MeO-TPP; Ar = Ph, 4-F-Ph). OsVI(Por)(NtBu)2 (Por = TPP, TTP, 4-C1-TPP, 3,4,5-MeO-TPP), OsVIO(Por)(NtBu) (Por = TPP, TTP, 4-C1-TPP, 3,4,5-MeO-TPP), and OsVIO(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)-(N2)(THF) with arylamines in aerobic tetrahydrofuran. Air oxidations of Os(Por)(H2NtBu)2 in tetrahydrofuran and in the presence of H2NtBu give OsO(Por)(NtBu) and Os(Por)(NtBu)2. The X-ray crystal structures of OsO-(TTP)(NtBu)·EtOH and Os(4-Cl-TPP)(NtBu)2 have been determined. Crystal data for OsO(TTP)(NtBu)·EtOH: monoclinic, space group P2l/c, a = 13.546(6) A, b = 23.180(3) A, c - 16.817(3) A, β = 90.84(2)°, V = 5279.7-(1.0) A3, Z = 4. Os(4-Cl-TPP)(NtBu)2: monoclinic, space group P2l/c, a = 11.046(2) A. b = 18.380(3) A, c = 23.640(4) A, β= 97.22(1)°, V = 4759.8(1.0) A, Z = 4. The Os=O and Os=NtBu distances in OsO(TTP)-(NtBu)·EtOH are 1.772(7) and 1.759(9) A, respectively. The Os=NtBu distances in Os(4-Cl-TPP)(NtBu)2 average 1.775 A. The imido angles range from 165.8(8) to 170.6(9)°. 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.
Synthesis, reactivity, and X-ray structural characterization of trans-dioxoosmium(VI) porphyrin complexes
Che, Chi-Ming,Chung, Wai-Cheung,Lai, Ting-Fong
, p. 2801 - 2804 (2008/10/08)
The oxidation of [Os(P)(CO)(EtOH)] (P = porphyrin dianion) to [Os(P)(O)2] by m-chloroperoxybenzoic acid in CH2Cl2 proceeds through a stable Os(IV) intermediate. The [Os(p-X-TPP)(O)2] (X = Cl, H, OMe, Me) and [Os
