title: Investigation on the trioctylphosphine oxide-based super-concentrated HCl system.
abstract: We report a new super-concentrated HCl system prepared by using trioctylphosphine oxide (TOPO)-based reverse micelles. The observed molar ratio between acid and water (nHCl/nH2O) in the super-concentrated HCl are much higher than that in the saturated aqueous HCl solution (0.28). Moreover, FT-IR spectroscopic results reveal that a significant amount of HCl remains in the molecular form rather than being ionized into H(+) and Cl(-). As a result, two H-Cl stretching bands can be observed in the FT-IR spectrum. The super-concentrated HCl provides a unique chemical environment in which many chemical substances occur in unusual states. For example, the color of super-concentrated HCl solution containing copper ion was found to be reddish brown rather than green as in conventional state. UV-Vis-NIR spectral results indicate that both d-d transition band of Cu(2+) and charge transfer band of Cl-Cu in super-concentrated HCl underwent significant variation. Additionally, copper ions bring about remarkable variation on the hydrogen bond network among HCl in the super-concentrated HCl solution as demonstrated by FT-IR spectra. According to the EXAFS results, we suggest that copper ion may occur as HCuCl3 in the super-concentrated HCl.
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Guo
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China; College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Guo
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China; Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Anqi
authors.initials: A
authors.lastname: He
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China; College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Beijing Synchrotron Radiation Facility (BSRF), Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Lirong
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China.
authors.forename: Tingguo
authors.initials: T
authors.lastname: Kang
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Xiuxiang
authors.initials: X
authors.lastname: Gao
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Shifu
authors.initials: S
authors.lastname: Weng
authors.affiliation: Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Zhanlan
authors.initials: Z
authors.lastname: Yang
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Yizhuang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, United States.
authors.forename: Isao
authors.initials: I
authors.lastname: Noda
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Jinguang
authors.initials: J
authors.lastname: Wu
mesh_terms: D003300:Copper / Q000032:analysis; D006851:Hydrochloric Acid / Q000737:chemistry*; D007477:Ions; D009682:Magnetic Resonance Spectroscopy; D009943:Organophosphorus Compounds / Q000737:chemistry; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D019265:Spectroscopy, Near-Infrared; D014867:Water / Q000737:chemistry
chemical_list: D007477:Ions; D009943:Organophosphorus Compounds; D012996:Solutions; D014867:Water; C044965:trioctyl phosphine oxide; D003300:Copper; D006851:Hydrochloric Acid
keywords: Copper ion; Super-concentrated HCl; Trioctylphosphine oxide (TOPO); n(H+)/n(H2O)