Wydział Chemii

Oksana V. Nesterova

Dmytro S. Nesterov

Julia Jezierska

Armando J. L. Pombeiro

Andrew Ozarowski

2018

Inorganic Chemistry

57

12384-12397

10.1021/acs.inorgchem.8b02145

Naukowa

Angielski

Artykuł

The novel coordination compounds [Cu₂(H^tBuDea)₂(OAc)₂] (1) and [Cu₂(HⁿBuDea)₂Cl₂]·nH₂O (2) have been prepared through the reaction of the respective copper(II) salts with N-tert-butyldiethanolamine (H₂^tBuDea, for 1) or N-butyldiethanolamine (H₂ⁿBuDea, for 2) in methanol solution. Crystallographic analysis reveals that, in spite of the common binuclear {Cu₂(μ-O)₂} core, the supramolecular structures of the complexes are drastically different. In 1 binuclear molecules are linked together by H-bonds into 1D chains, while in 2 the neighboring pairs of binuclear molecules are H-bonded, forming tetranuclear aggregates. Variable-temperature (1.8–300 K) magnetic susceptibility measurements of 1 and 2 show a dominant antiferromagnetic behavior. Both complexes are also studied by HF-EPR spectroscopy. While the interaction between Cu(II) centers in 1 can be described by a single coupling constant J = 130.1(3) cm^–1 (using H = JS₁S₂), the crystallographically different {Cu₂(μ-O)₂} pairs in 2 are expected exchange from ferro- to antiferromagnetic behavior (with J ranging from −32 to 110 cm^–1, according to DFT calculations). Complexes 1 and 2 act as catalysts in the amidation of cyclohexane with benzamide, employing ^tBuOO^tBu as oxidant. The maximum achieved conversion of benzamide (20%, after 24 h reaction time) was observed in the 1/^tBuOO^tBu system. In the cases of ^tBuOO(O)CPh or ^tBuOOH oxidants, no significant amidation product was observed, while for ^tBuOO(O)CPh, the oxidative dehydrogenation of cyclohexane occurred, giving cyclohexene, to afford the allylic ester (cyclohex-2-en-1-yl benzoate) as the main reaction product.

https://doi.org/10.1021/acs.inorgchem.8b02145

https://www.acs.org/content/acs/en.html