Coordination Chemistry of Aliphatic, Tripodal Ligands with Zinc Salts

Abstract

The unsymmetrical, aliphatic tripods N(CH2CH2CH2NH2)2(CH2CH2OH)(H5‐2) and N(CH2CH2CH2NH2)2(CH2CH2CH2OH) (H5‐4) were prepared and their coordination chemistry with zinc salts was studied. The reactivity of the ligands with zinc chloride, zinc perchlorate and zinc bis(tetrafluoroborate) depends on the anion present. Ligand H5‐2 reacts with Zn(ClO4)2 under formation of the dinuclear centrosymmetric complex [(H4‐2)Zn]2(ClO4)2 (5) containing bridging η2‐alkoxy functions. Ligand H5‐2 reacts with Zn(BF4)2 under formation of the trigonal‐bipyramidal complex [(H5‐2)ZnF]BF4 (7), while the reaction of (H5‐4) with ZnCl2 yields the mononuclear, tetrahedral complex [(H5‐4)ZnCl]Cl (8) with an uncoordinated alcohol donor group. Complexes 5, 7 and 8 were characterized by X‐ray diffraction and NMR and IR spectroscopy.

Metallacycles of Iron, Zinc, and Cadmium Assembled by Polytopic Bis(pyrazolyl)methane Ligands and Fluoride Abstraction from BF4-

“…Numerous examples of fluoride ions bridging zinc cations in extended networks are known, and their Zn−F distances usually fall within the range of 1.95−2.10 Å. − Terminal fluoride ligands on zinc are less common, and their Zn−F distances are typically shorter (ca. 1.85 Å), although a long terminal Zn−F bond of 2.04 Å has been claimed …”

Hyperpolarized 15N-labeled, deuterated tris(2-pyridylmethyl)amine as an MRI sensor of freely available Zn2+

“…This was also evident in 15 N NMR spectra of TPA, whose chemical shift did not change between pH 6.4 and 8.0. The TPA binding unit is commonly used in optical probe designs because of its high affinity and specificity for Zn 2+ (log K ZnTPA = −11.0) 26,27,42 .…”

Catechol Oxidation with Dinuclear Copper Complexes of Aliphatic Tripodal Amino Alcohols

“…Ligand Syntheses: Ligands NNO 2 ‐222 (H 4 ‐ 2 ),4c NNO 2 ‐223 (H 4 ‐ 3 ),6b NNO 2 ‐233 (H 4 ‐ 4 ),3i NNO 2 ‐322 (H 4 ‐ 5 ),7 and NN 2 O‐332 (H 5 ‐ 1 )5 were prepared according to previously published procedures.…”

“…The field of aliphatic tripodal ligands with unsymmetrical donor functions developed more recently. Some complexes of the unsymmetrical aliphatic tripodal ligands NN 2 O‐222 (H 5 ‐ A ),4 NN 2 O‐332 (H 5 ‐ 1 ), NN 2 O‐333 (H 5 ‐ B ),5 NNO 2 ‐222 (H 4 ‐ 2 ),4c NNO 2 ‐233 (H 4 ‐ 4 ),3i NNO 2 ‐223 (H 4 ‐ 3 ),6 and NNO 2 ‐322 (H 4 ‐ 5 )7 have been prepared (Figure 1). Complexes of sulfur containing unsymmetrical tripodal ligands have also been reported 8…”