Synthesis, and molecular sensing behavior of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl], dpksc = di-2-pyridyl ketone semicarbazone

Mohammed Bakir; Ordel Brown

doi:10.1016/j.molstruc.2012.07.047

Synthesis, and molecular sensing behavior of fac-[Re(CO) ₃(κ²-N,N-dpksc)Cl], dpksc = di-2-pyridyl ketone semicarbazone

Mohammed Bakir^*, Ordel Brown

^*Corresponding author for this work

McCormick Office of Undergraduate Engineering

Research output: Contribution to journal › Article › peer-review

2 Scopus citations

Abstract

When [Re(CO)₅Cl] was allowed to react with di-2-pyridyl ketone semicarbazone hydrochloride (dpksc.HCl) in refluxing toluene, fac-[Re(CO) ₃(κ²-N,N-dpksc)Cl] was isolated. The identity of fac-[Re(CO)₃(κ²-N,N-dpksc)Cl] was elucidated from the results of its elemental analysis and confirmed using a number of spectroscopic measurements. Spectroscopic measurements done on non-aqueous solvents divulged sensitivity of fac-[Re(CO)₃(κ²-N, N-dpksc)Cl] to changes in its surroundings. ¹H NMR studies revealed significant solvent dependence as manifested by the chemical shift variations; the exchange of the amine protons with solvent deuterium in CDCl₃ and d₆-acetone; the temperature dependence of the chemical shifts of the amine and amide protons and insignificant temperature dependence of the aromatic proton. The electronic absorption spectra of fac-[Re(CO) ₃(κ²-N,N-dpksc)Cl] measured on non-aqueous solvents disclosed two high energy intra-ligand charge transfer (ILCT) transitions. Optical measurements performed on protophilic solutions of fac-[Re(CO) ₃(κ²-N,N-dpksc)Cl] in the presence of bases and acids showed the appearance and disappearance of a low energy ILCT electronic transitions and established reversible inter-conversion between fac-[Re(CO) ₃(κ²-N,N-dpksc)Cl] and its conjugate base, fac-[Re(CO)₃(κ²-N,N-dpksc-H)Cl]^-. Thermo-optical measurements done on protophilic solutions of fac-[Re(CO) ₃(κ²-N,N-dpksc)Cl] disclosed the absence of thermal acid-base inter-conversion between fac-[Re(CO)₃(κ²- N,N-dpksc)Cl] and fac-[Re(CO)₃(κ²-N,N-dpksc-H)Cl] ^- and established reversible electronic transfer between the high energy electronic transitions of fac-[Re(CO)₃(κ²-N, N-dpksc)Cl]. Optosensing measurements done on protophilic solutions of fac-[Re(CO)₃(κ²-N,N-dpksc)Cl] showed acids and bases in concentrations as low as 1.00 × 10^-10 M can be detected and determined using protophilic solutions of of fac-[Re(CO)₃(κ ²-N,N-dpksc)Cl]. Electrochemical measurements on dmf solutions of fac-[Re(CO)₃(κ²-N,N-dpksc)Cl] showed irreversible electrochemical redox process and electrochemically generated product waves pointing to the instability of fac-[Re(CO)₃(κ²-N,N- dpksc)Cl] to redox transformations.

Original language	English (US)
Pages (from-to)	118-125
Number of pages	8
Journal	Journal of Molecular Structure
Volume	1032
DOIs	https://doi.org/10.1016/j.molstruc.2012.07.047
State	Published - Jan 30 2013

Keywords

Di-2-pyridyl ketone semicarbazone
Electrochemistry
Rhenium
Sensors
Spectroscopy
Synthesis

ASJC Scopus subject areas

Analytical Chemistry
Spectroscopy
Organic Chemistry
Inorganic Chemistry

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10.1016/j.molstruc.2012.07.047

Cite this

@article{439a066961274887b901c3bf15097c8c,

title = "Synthesis, and molecular sensing behavior of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl], dpksc = di-2-pyridyl ketone semicarbazone",

abstract = "When [Re(CO)5Cl] was allowed to react with di-2-pyridyl ketone semicarbazone hydrochloride (dpksc.HCl) in refluxing toluene, fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] was isolated. The identity of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] was elucidated from the results of its elemental analysis and confirmed using a number of spectroscopic measurements. Spectroscopic measurements done on non-aqueous solvents divulged sensitivity of fac-[Re(CO)3(κ2-N, N-dpksc)Cl] to changes in its surroundings. 1H NMR studies revealed significant solvent dependence as manifested by the chemical shift variations; the exchange of the amine protons with solvent deuterium in CDCl3 and d6-acetone; the temperature dependence of the chemical shifts of the amine and amide protons and insignificant temperature dependence of the aromatic proton. The electronic absorption spectra of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] measured on non-aqueous solvents disclosed two high energy intra-ligand charge transfer (ILCT) transitions. Optical measurements performed on protophilic solutions of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] in the presence of bases and acids showed the appearance and disappearance of a low energy ILCT electronic transitions and established reversible inter-conversion between fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] and its conjugate base, fac-[Re(CO)3(κ2-N,N-dpksc-H)Cl]-. Thermo-optical measurements done on protophilic solutions of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] disclosed the absence of thermal acid-base inter-conversion between fac-[Re(CO)3(κ2- N,N-dpksc)Cl] and fac-[Re(CO)3(κ2-N,N-dpksc-H)Cl] - and established reversible electronic transfer between the high energy electronic transitions of fac-[Re(CO)3(κ2-N, N-dpksc)Cl]. Optosensing measurements done on protophilic solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] showed acids and bases in concentrations as low as 1.00 × 10-10 M can be detected and determined using protophilic solutions of of fac-[Re(CO)3(κ 2-N,N-dpksc)Cl]. Electrochemical measurements on dmf solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] showed irreversible electrochemical redox process and electrochemically generated product waves pointing to the instability of fac-[Re(CO)3(κ2-N,N- dpksc)Cl] to redox transformations.",

keywords = "Di-2-pyridyl ketone semicarbazone, Electrochemistry, Rhenium, Sensors, Spectroscopy, Synthesis",

author = "Mohammed Bakir and Ordel Brown",

year = "2013",

month = jan,

day = "30",

doi = "10.1016/j.molstruc.2012.07.047",

language = "English (US)",

volume = "1032",

pages = "118--125",

journal = "Journal of Molecular Structure",

issn = "0022-2860",

publisher = "Elsevier",

}

TY - JOUR

T1 - Synthesis, and molecular sensing behavior of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl], dpksc = di-2-pyridyl ketone semicarbazone

AU - Bakir, Mohammed

AU - Brown, Ordel

PY - 2013/1/30

Y1 - 2013/1/30

N2 - When [Re(CO)5Cl] was allowed to react with di-2-pyridyl ketone semicarbazone hydrochloride (dpksc.HCl) in refluxing toluene, fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] was isolated. The identity of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] was elucidated from the results of its elemental analysis and confirmed using a number of spectroscopic measurements. Spectroscopic measurements done on non-aqueous solvents divulged sensitivity of fac-[Re(CO)3(κ2-N, N-dpksc)Cl] to changes in its surroundings. 1H NMR studies revealed significant solvent dependence as manifested by the chemical shift variations; the exchange of the amine protons with solvent deuterium in CDCl3 and d6-acetone; the temperature dependence of the chemical shifts of the amine and amide protons and insignificant temperature dependence of the aromatic proton. The electronic absorption spectra of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] measured on non-aqueous solvents disclosed two high energy intra-ligand charge transfer (ILCT) transitions. Optical measurements performed on protophilic solutions of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] in the presence of bases and acids showed the appearance and disappearance of a low energy ILCT electronic transitions and established reversible inter-conversion between fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] and its conjugate base, fac-[Re(CO)3(κ2-N,N-dpksc-H)Cl]-. Thermo-optical measurements done on protophilic solutions of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] disclosed the absence of thermal acid-base inter-conversion between fac-[Re(CO)3(κ2- N,N-dpksc)Cl] and fac-[Re(CO)3(κ2-N,N-dpksc-H)Cl] - and established reversible electronic transfer between the high energy electronic transitions of fac-[Re(CO)3(κ2-N, N-dpksc)Cl]. Optosensing measurements done on protophilic solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] showed acids and bases in concentrations as low as 1.00 × 10-10 M can be detected and determined using protophilic solutions of of fac-[Re(CO)3(κ 2-N,N-dpksc)Cl]. Electrochemical measurements on dmf solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] showed irreversible electrochemical redox process and electrochemically generated product waves pointing to the instability of fac-[Re(CO)3(κ2-N,N- dpksc)Cl] to redox transformations.

AB - When [Re(CO)5Cl] was allowed to react with di-2-pyridyl ketone semicarbazone hydrochloride (dpksc.HCl) in refluxing toluene, fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] was isolated. The identity of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] was elucidated from the results of its elemental analysis and confirmed using a number of spectroscopic measurements. Spectroscopic measurements done on non-aqueous solvents divulged sensitivity of fac-[Re(CO)3(κ2-N, N-dpksc)Cl] to changes in its surroundings. 1H NMR studies revealed significant solvent dependence as manifested by the chemical shift variations; the exchange of the amine protons with solvent deuterium in CDCl3 and d6-acetone; the temperature dependence of the chemical shifts of the amine and amide protons and insignificant temperature dependence of the aromatic proton. The electronic absorption spectra of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] measured on non-aqueous solvents disclosed two high energy intra-ligand charge transfer (ILCT) transitions. Optical measurements performed on protophilic solutions of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] in the presence of bases and acids showed the appearance and disappearance of a low energy ILCT electronic transitions and established reversible inter-conversion between fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] and its conjugate base, fac-[Re(CO)3(κ2-N,N-dpksc-H)Cl]-. Thermo-optical measurements done on protophilic solutions of fac-[Re(CO) 3(κ2-N,N-dpksc)Cl] disclosed the absence of thermal acid-base inter-conversion between fac-[Re(CO)3(κ2- N,N-dpksc)Cl] and fac-[Re(CO)3(κ2-N,N-dpksc-H)Cl] - and established reversible electronic transfer between the high energy electronic transitions of fac-[Re(CO)3(κ2-N, N-dpksc)Cl]. Optosensing measurements done on protophilic solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] showed acids and bases in concentrations as low as 1.00 × 10-10 M can be detected and determined using protophilic solutions of of fac-[Re(CO)3(κ 2-N,N-dpksc)Cl]. Electrochemical measurements on dmf solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] showed irreversible electrochemical redox process and electrochemically generated product waves pointing to the instability of fac-[Re(CO)3(κ2-N,N- dpksc)Cl] to redox transformations.

KW - Di-2-pyridyl ketone semicarbazone

KW - Electrochemistry

KW - Rhenium

KW - Sensors

KW - Spectroscopy

KW - Synthesis

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U2 - 10.1016/j.molstruc.2012.07.047

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JO - Journal of Molecular Structure

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