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The SARS-CoV-2 virus outbreak has created turmoil in domestic economies around the world. The changes are visible in all industrial branches of the economy, including the market of metallic raw materials. The article reviews and analyzes the size of changes in the production and sales of copper and copper products in Poland in 2020, comparing the data in the previous years. The aim of the article is to assess the possible impact of the epidemic and related economic changes on the copper market in Poland.

The SARS-CoV-2 virus outbreak has created turmoil in domestic economies around the world. The changes are visible in all industrial branches of the economy, including the market of metallic raw materials. The article reviews and analyzes the size of changes in the production and sales of copper and copper products in Poland in 2020, comparing the data in the previous years. The aim of the article is to assess the possible impact of the epidemic and related economic changes on the copper market in Poland.

[Cu4(succinato)(tpmc)2](ClO4) 6 · 2H2O (tpmc = N,N′,N″,N‴-tetrakis-(2-pyridylmethyl)-1,4,8,11-tetraa zacyclotetradecane, succinato = dianion of succinic acid) has been prepared and characterized by elemental analysis, UV/vis, IR, EPR (X-band) spectra, conductivity and magnetization measurements (SQUID). Based on a low-temperature measurements (100(2) K), X-ray analyses of the first tetranuclear Cu(II)-tpmc complex, single crystal of which corresponded to the [Cu4(succinato)(tpmc)2](ClO4) 6·2C2H5OH·4H2O (1) and of the previously described [Cu2(C6H5COO)tpmc](ClO4) 3·0.5CH3OH·0.5H2O (2) were also done. The complexes crystallize in triclinic P over(1, ̄) (1) and monoclinic P21/c (2) space groups. The geometry around the first Cu(II) coordination sphere in the tetranuclear complex (1) is almost regular square-based pyramidal, while significant distortion around the other metallic center was observed. The angular structural parameter (τ), which is applicable to five coordinate structures as an index of degree of trigonality, was found to be 0.05 and 0.40, respectively. In the binuclear complex (2) the geometry around the first Cu(II) coordination sphere is regular square-based pyramidal (τ = 0.09), while around the other is distorted trigonal bipyramidal (τ = 0.79). In complexes (1) and (2) the bridging carboxylate groups are coordinated to metallic centres in a syn-anti mode. Weak ferromagnetic interactions are observed between copper(II) ions, connected through syn-anti monocarboxylate bridges (2J = +1.26 and +1.84 cm-1 in complexes (1) and (2), respectively). Additional antiferromagnetic interaction through succinato anion (zJ′ = -1.57 cm-1) gives finally rise to antiferromagnetic interactions, observed in magnetic measurements in tetrameric complex (1).

The reaction of readily accessible (3-furyl)allylamines with maleic anhydride, followed by a domino sequence involving acylation/cycloaddition/proton shift steps, led to the formation of furo[2,3-f]isoindoles - the aza-analogs of pinguisane-type sesquiterpenes. The key intramolecular Diels-Alder vinylfuran (IMDAV) reaction proceeded under mild conditions, with high levels of diastereoselectivity and satisfactory yields. © 2015 Elsevier Ltd.