Metal‐Ion Induced In Situ Ligand Oxidation for Self‐Assembled Clusters: from Bis(5‐(2‐pyridine‐2‐yl)‐1,2,4‐triazole‐3‐yl)methane to Alcohol or Ketone

Abstract

Hydrothermal reactions of metal nitrates and ligand bis(5-(pyridine-2-yl)-1,2,4-triazol-3-yl)methane (H L ) gave three cluster compounds, {Cr }, {Zn } and {Fe }. Notably, methylene group of H L was in situ oxidized either to hydroxymethylated (L -O) in the metallo-ring {Zn } or to a rigid carbonylated (L =O) in the screw-type {Fe }. In light of comparative experimental results, NO was deduced to be of a catalytic role in the ligand oxidation. Metal ion could be regarded as an "induced" tool for clusters generation in self-assembly process.

In Situ Metal–Ligand Reactions under Solvent-Dependent Hydro(solvo)thermal Conditions: Structures, Mass Spectrometry, and Magnetism

“…In this study, bis­(triazolyl)­methane and its derivatives were selected as the appropriate ligands to react with metal ion under hydro­(solvo)­thermal conditions for the following reasons: (i) the ligands containing triazole rings have various bridging modes and excellent coordination properties; , (ii) the C atom of methylene could be activated by two triazole parts in the presence of metal centers; , (iii) the protonated N atoms on triazoles provide reaction sites for condensation formation. To this end, under hydro­(solvo)­thermal conditions starting from a bis­(pyridinetriazolyl)­metanane (H 2 L 0 ), in the presence of Dy III ions, six interesting organic ligands (H 2 L 1 ,H 4 L 2 , H 2 L 3 , HL 4 , HL 5 , and HL 6 ; Scheme ), synthesized from oxidation, nitration, condensation, and C–C coupling in situ reaction, have been detected in eight new Dy III coordination complexes, namely, [Dy­(H 2 L 0 )­(NO 3 )­(H 2 O) 3 ]·2NO 3 ·H 2 O ( 1 ), [Dy­(L 1 )­(Ac)­(H 2 O) 3 ]·4.5H 2 O ( 2 ), [Dy­(L 1 )­(μ 2 -OH)] n ·3H 2 O ( 3 ), [Dy 2 (L 2 )­(NO 3 ) 2 (H 2 O) 6 ]·2H 2 O ( 4 ), Dy­(H 2 L 3 )­(NO 3 ) 2 (H 2 O) ( 5 ), Dy­(HL 4 )­(NO 3 ) 3 ( 6 ), Dy 4 (L 5 ) 2 (μ 3 -OH) 2 (Ac) 6 (NO 3 ) 2 ( 7 ), and Dy 4 (L 6 ) 2 (μ 3 -OH) 2 (Ac) 6 (NO 3 ) 2 ( 8 ).…”