112193-82-5Relevant articles and documents
Cosmosen: Octa-Armed 24-Membered Cyclic Octaamine Synthesized from a Byproduct in the Preparation of 4-Benzyl-2,6-dioxocyclen
Ju, Huiyeong,Iwase, Miki,Sako, Hikari,Horita, Hiroki,Koike, Shiori,Lee, Eunji,Ikeda, Mari,Kuwahara, Shunsuke,Habata, Yoichi
, p. 9847 - 9853 (2021)
The synthesis of an octa-armed 24-membered cyclic octaamine (1) is reported. When 4-benzyl-1,4,7,10-tetraazacyclododecane-2,6-dione (3a) was prepared by the reaction of diethylenetriamine with diethyl N-benzyliminodiacetate (2), a dimeric macrocycle (3b) was obtained as a byproduct in a 5% yield. An octa-armed 24-membered cyclic octaamine (1), named Cosmosen, was prepared via the reductive amination and reduction of 3b. The binding constants for the 1:1 and 2:1 (Ag+/1) complexation of 1 were estimated to be ca. 7.9 and 13.9, respectively, by titration experiments using UV-vis spectrometry in methanol and chloroform (v/v, 9:1) solutions at 298 K.
Bis-Argentivorous Molecules Bridged by Phenyl and 4,4′-Biphenyl Groups: Structural and Dynamic Behavior of Silver Complexes
Habata, Yoichi,Horita, Hiroki,Ikeda, Mari,Iwase, Miki,Ju, Huiyeong,Kaneko, Nanae,Kuwahara, Shunsuke,Yagi, Ken-Ichi
, p. 15159 - 15168 (2021/10/20)
Bis-argentivorous molecules (La and Lb), which have phenyl and 4,4′-biphenyl groups as linkers, have been prepared. The structures of Ag+ complexes with the new ligands (La and Lb) were investigated in solution and the solid state. The CSI-MS and 1H NMR titration of La and Lb with Ag+ show 1:1 and 1:2 complexes depending on the [Ag+]:[L] ratios. In the solid-state structures, single crystals of La and Lb with 2 equiv of Ag+ were prepared. X-ray crystallography of the silver(I) complexes with La and Lb showed that an intramolecular racemic structure (Δ(δδδδ)D(λλλλ) form) and a racemic mixture of Δ(δδδδ)Δ(δδδδ) and D(λλλλ)D(λλλλ) forms were formed, respectively. The dynamic 1H NMR studies suggest the following: (i) the activation entropies (ΔSL) of the side arm rotations in the Ag+ complex with La were all negative, indicating restricted rotation of the side arms due to their shortness, and (ii) the ΔSL values of the Ag+ complexes with Lb were negative only when the side arms of both cyclens rotated simultaneously, and the ΔSL values for the 1:1 and 1:2 complexes were positive when one cyclen side arm was rotated. These values of ΔSL indicate that the biphenyl side arms between the two cyclens are not long enough to rotate the ring freely.