TY - JOUR
T1 - Revisiting the reactivity of tetrachloroauric acid with
T2 - N, N -bidentate ligands: Structural and spectroscopic insights
AU - Mertens, R. Tyler
AU - Kim, Jong Hyun
AU - Jennings, Will C.
AU - Parkin, Sean
AU - Awuah, Samuel G.
N1 - Publisher Copyright:
© 2019 The Royal Society of Chemistry.
PY - 2019
Y1 - 2019
N2 - The reactivity of tetrachloroauric acid (HAuCl 4 ) with readily accessible bidentate N-donor ligands affords N,N-ligated Au(iii) center complexes. These compounds are useful precursors of stable catalysts, anticancer agents, and building blocks for materials. This report provides detailed insight into intermediates, equilibria, the counter anion effect, and structural variability, using spectroscopy, crystallography and computational tools. Novel mixed-valence Au(i) and Au(iii) complexes [Au(o-phen)Cl 2 ] 2 [AuCl 2 ][AuCl 4 ] and [Au(o-phen)Cl 2 ][AuCl 2 ] having AuCl 2 - and AuCl 4 - anions linearly arranged in the axial sites of the square-planar Au(o-phen)Cl 2 cation were discovered. Other competing side products of the reaction studied revealed protonated N,N-bidentate ligands with AuCl 4 - anions. Quantitative variable temperature NMR studies reveal that for a mixture of target Au(iii) salt and the protonated ligand, the reaction favors the irreversible formation of the side product. Using a rapid (30 min) temperature controlled protocol, the desired coordinated species is accessible in respectable yields while avoiding side products.
AB - The reactivity of tetrachloroauric acid (HAuCl 4 ) with readily accessible bidentate N-donor ligands affords N,N-ligated Au(iii) center complexes. These compounds are useful precursors of stable catalysts, anticancer agents, and building blocks for materials. This report provides detailed insight into intermediates, equilibria, the counter anion effect, and structural variability, using spectroscopy, crystallography and computational tools. Novel mixed-valence Au(i) and Au(iii) complexes [Au(o-phen)Cl 2 ] 2 [AuCl 2 ][AuCl 4 ] and [Au(o-phen)Cl 2 ][AuCl 2 ] having AuCl 2 - and AuCl 4 - anions linearly arranged in the axial sites of the square-planar Au(o-phen)Cl 2 cation were discovered. Other competing side products of the reaction studied revealed protonated N,N-bidentate ligands with AuCl 4 - anions. Quantitative variable temperature NMR studies reveal that for a mixture of target Au(iii) salt and the protonated ligand, the reaction favors the irreversible formation of the side product. Using a rapid (30 min) temperature controlled protocol, the desired coordinated species is accessible in respectable yields while avoiding side products.
UR - http://www.scopus.com/inward/record.url?scp=85061141411&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85061141411&partnerID=8YFLogxK
U2 - 10.1039/c8dt04960b
DO - 10.1039/c8dt04960b
M3 - Article
C2 - 30657507
AN - SCOPUS:85061141411
SN - 1477-9226
VL - 48
SP - 2093
EP - 2099
JO - Dalton Transactions
JF - Dalton Transactions
IS - 6
ER -