Assembling Hexagonal‐Bipyramidal {Mn8Zn2} and {Mn8Zn4} Clusters. Issue 32 (5th September 2022)

• Record Type: Journal Article
• Authors: Tziotzi, Thomais G.; Andreou, Evangelos K.; Mavromagoulos, Athanasios; Murrie, Mark; Dalgarno, Scott J.; Brechin, Euan K.; Milios, Constantinos J.
• Is Part Of: European journal of inorganic chemistry. Volume 2022:Issue 32(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-05
• Subjects: Heterometallic clusters -- Magnetic properties -- Manganese -- Synthesis design -- Zinc; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.202200434
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: Reaction between Mn(NO3 )2 ⋅ 6H2 O, Zn(NO3 )2 ⋅ 6H2 O, 1, 3, 5‐tri(2‐hydroxyethyl)‐1, 3, 5‐triazacyclohexane (H3 L) and pyrazole in MeOH under basic conditions leads to the formation of the decanuclear complex [Mn III 6 Mn II 2 Zn II 2 (L)2 (pyr)4 O4 (OH)4 (NO3 )2 (MeOH)2 (H2 O)4 ](NO3 )2 ⋅ Η2 Ο (1 ⋅ Η2 Ο). The metallic core of the cationic cluster consists of a central hexagonal‐bipyramidal {Mn III 4 Mn II 2 Zn II 2 } unit connected to two peripheral trivalent Mn centers arranged in a "trans" fashion, with one Mn III center lying above and one Mn III center below the hexagonal plane. Replacing Mn(NO3 )2 ⋅ 6H2 O with MnBr2 ⋅ 4H2 O and repeating the same reaction leads to the formation of the related, neutral decanuclear complex [Mn III 6 Mn II 2 Zn II 2 (L)2 (pyr)4 O4 (OH)4 Br4 (H2 O)2 ] (2 ), displaying the same metallic core as 1 . Addition of THF to the reaction mixture that produces (2 ) affords the neutral dodecanuclear complex [Mn III 6 Mn II 2 Zn II 4 (L)2 (pyr)6 O4 (OH)4 Br6 (H2 O)4 ] ⋅ 8THF (3 ⋅ 8THF), whose metallic skeleton retains the central hexagonal‐bipyramidal {Mn III 4 Mn II 2 Zn II 2 } unit found in 1 and 2 but is now connected to two peripheral {Mn III Zn II } units. Magnetic susceptibility and magnetization measurements carried out in the T =2–300 K temperature range and in fields up to B =7.0 T for all three complexes reveal dominant antiferromagnetic exchange interactions. Abstract : The use of the 1, 3, 5‐tri(2‐hydroxyethyl)‐1, 3, 5‐triazacyclohexane ligand in mixed‐metal manganese/zinc chemistry leads to the synthesis of three closely related complexes; two decanuclear {Mn III 6 Mn II 2 Zn II 2 } clusters and one dodecanuclear {Mn III 6 Mn II 2 Zn II 4 } cluster, all of which display similar structures based on a hexagonal‐bipyramidal {Mn6 Zn2 } central unit.