《Two ways of spin crossover in an iron(II) coordination polymer associated with conformational changes of a bridging ligand》 was published in Dalton Transactions in 2020. These research results belong to Ksiazek, Maria; Weselski, Marek; Dreczko, Agnieszka; Maliuzhenko, Vladyslav; Kazmierczak, Marcin; Toloczko, Aleksandra; Kusz, Joachim; Bronisz, Robert. Name: 1H-1,2,3-Triazole The article mentions the following:
1,4-Di(1-ethyl-1,2,3-triazol-5-yl)butane (bbtre) was prepared by lithiation of 1-ethyl-1,2,3-triazole, followed by alkylation with 1,4-dibromobutane. The ligand bbtre forms a three-dimensional network with Fe(II), [Fe(bbtre)3](ClO4)2·2CH3CN, that exhibits thermally induced spin crossover (SCO). A change of temperature or change of spin state results in various types of structural transformation, leading to different structures that are stable in strictly defined temperature ranges. As a result, there are three spin crossover transitions arranged via two different paths. Thus, cooling <280 K involves a HT(HS) → LT(HS) (HT, high temperature structure; LT, low temperature structure; HS, high spin) phase transition (PT), which is associated with conformational changes of the bbtre mols. and with deformation of the polymeric skeleton. In the LT phase incomplete and reversible LT(HS) ⇄ LT(HS/LS) spin crossover occurs (LS, low spin). In contrast, rapid cooling (of a sample not previously thermally treated) allows the HT(HS) → LT(HS) phase transition to be avoided, and so complete HT(HS) → HT1(LS) SCO occurs. This means that the PT plays the role of a switch, which allows a choice of one of two ways in which the SCO will proceed. After rapid cooling, further heating to 150 K and subsequent cooling results in a reversible HT1(HS) ⇄ HT1(LS) spin crossover (T↓1/2 = 130 K, T↑1/2 = 131 K). However, raising the temperature to 170-200 K gives a modulated structure HT2(HS) exhibiting the next reversible HT2(HS) ⇄ HT2(LS) SCO (T↓1/2 = 121 K, T↑1/2 = 123 K). Finally, heating >200 K involves the HT2(HS) → LT(HS) PT and results in a LT(HS) structure exhibiting incomplete LT(HS) ⇄ LT(HS/LS) spin crossover. In the experimental materials used by the author, we found 1H-1,2,3-Triazole(cas: 288-36-8Name: 1H-1,2,3-Triazole)
1H-1,2,3-Triazole(cas: 288-36-8) belongs to triazoles. Triazoles are an important group of nitrogen-containing five-membered heterocyclic scaffolds. Triazoles are core structures of several drugs and pharmaceutical agents. Triazole derivatives possess antimicrobial, antiparasitic, antidiabetic, analgesic, and anti-inflammatory properties Name: 1H-1,2,3-Triazole
Referemce:
1,2,3-Triazole – Wikipedia,
Triazoles – an overview | ScienceDirect Topics