Ligand-forced dimerization of copper(I)–olefin complexes bearing a 1,3,4-thiadiazole core

Abstract

As an important class of heterocyclic compounds, 1,3,4-thiadiazoles have a broad range of potential applications in medicine, agriculture and materials chemistry, and were found to be excellent precursors for the crystal engineering of organometallic materials. The coordinating behaviour of allyl derivatives of 1,3,4-thiadiazoles with respect to transition metal ions has been little studied. Five new crystalline copper(I) π-complexes have been obtained by means of an alternating current electrochemical technique and have been characterized by single-crystal X-ray diffraction and IR spectroscopy. The compounds are bis[μ-5-methyl-N-(prop-2-en-1-yl)-1,3,4-thiadiazol-2-amine]bis[nitratocopper(I)], [Cu(NO)(CHNS)], (1), bis[μ-5-methyl-N-(prop-2-en-1-yl)-1,3,4-thiadiazol-2-amine]bis[(tetrafluoroborato)copper(I)], [Cu(BF)(CHNS)], (2), μ-aqua-bis{μ-5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine}bis[nitratocopper(I)], [Cu(NO)(CHNS)(HO)], (3), μ-aqua-(hexafluorosilicato)bis{μ-5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine}dicopper(I)-acetonitrile-water (2/1/4), [Cu(SiF)(CHNS)(HO)]·0.5CHCN·2HO, (4), and μ-benzenesulfonato-bis{μ-5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine}dicopper(I) benzenesulfonate-methanol-water (1/1/1), [Cu(CHOS)(CHNS)](CHOS)·CHOH·HO, (5). The structure of the ligand 5-methyl-N-(prop-2-en-1-yl)-1,3,4-thiadiazol-2-amine (Mepeta), CHNS, was also structurally characterized. Both Mepeta and 5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine (Pesta) (denoted L) reveal a strong tendency to form dimeric {CuL} fragments, being attached to the metal atom in a chelating-bridging mode via two thiadiazole N atoms and an allylic C=C bond. Flexibility of the {Cu(Pesta)} unit allows the Cu atom site to be split into two positions with different metal-coordination environments, thus enabling the competitive participation of different molecules in bonding to the metal centre. The Pesta ligand in (4) allows the Cu atom to vary between water O-atom and hexafluorosilicate F-atom coordination, resulting in the rare case of a direct Cu...FSiF interaction. Extensive three-dimensional hydrogen-bonding patterns are formed in the reported crystal structures. Complex (5) should be considered as the first known example of a Cu(CHSO) coordination compound. To determine the hydrogen-bond interactions in the structures of (1) and (2), a Hirshfeld surface analysis has been performed.

Cu(I) Arylsulfonate π-Complexes with 3-Allyl-2-thiohydantoin: The Role of the Weak Interactions in Structural Organization

“…In our previous works we have shown an impact of a weak interactions, including hydrogen bonding, on the structural organization in π-complex compounds. [28][29][30] The weakening of the Cu-O interaction in 2 (and the strengthening of Cu-S as a result) can be explained by the fact, that the anion in 2 is involved in a larger number of the H-bonding, due to the presence of the water molecule, all of which competes with the Cu-O interaction. Finally, since the water was presented in both reaction mixtures, but co-crystallized only in 2, its presence in its crystal structure should be explained by the different character of benzene-and p-toluenesulfonate anions.…”

Copper(I) chloride and copper(I) perchlorate π-complexes with 2-allylthio-5-methyl-1,3,4-thiadiazole: synthesis and crystal structure

“…Похідні 1,3,4-тіадіазолів володіють широким спектром фармакологічних властивостей (антибактеріальною, протигрибковою, протитуберкульозною, протизапальною, анальгетичною тощо), їх використовують для створення матеріалів з важливими оптичними, магнітним та люмінесцентними властивостями, а також застосовують у кристалічній інженерії різноманітних металокомплексів [1][2][3][4][5][6][7]. Незважаючи на те, що комплексоутворення іонів d-металів з лігандами, що містять у своєму складі тіадіазольне ядро, інтенсивно досліджувалось впродовж декількох десятиліть, сьогодні відомо лише близько тридцяти структурно вивчених π-координаційних сполук на основі алільних похідних 1,3,4-тіадіазолів.…”

Crystal structure of tetra-μ-acetato-bis[(5-amino-2-methylsulfanyl-1,3,4-thiadiazole-κN 1)copper(II)]

“…Their diverse biological activity possibly arises from the presence of the NCS moiety in the molecule (Oruç et al, 2004). An interesting feature of the metal-ligand chemistry of these compounds is that the complexes can be either mononuclear (Tzeng et al, 2004;Varna et al, 2018;Qiu et al, 2014) or binuclear (Deckert et al, 2016;Ardan et al, 2017). A search of the Cambridge Structural Database (CSD Version 5.4, update of February 2019; Groom et al, 2016) revealed that although crystal structures have been reported for complexes of either 1,3,4-thiadiazole derivatives or OAc with a number of metal ions, including zinc, copper, nickel, manganese, cadmium, cobalt and palladium, no examples are known of mixed-ligand metal complexes containing both 1,3,4-thiadiazole derivatives and OAc.…”