Preparation and Characterization of Dinuclear Nickel(II) Complexes Containing N3Ni(μ1, 3‐SO3R)2(μ‐RCN4)NiN3 Cores: Crystal Structures and Magnetic Properties1. Issue 3 (18th February 2013)

• Record Type: Journal Article
• Authors: Lach, Jochen; Perlt, Eva; Kirchner, Barbara; Kersting, Berthold
• Is Part Of: Zeitschrift für anorganische und allgemeine Chemie. Volume 639:Issue 3/4(2013)
• Page Start: 524
• Page End: 532
• Publication Date: 2013-02-18
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1002/zaac.201200501
• Languages: English
• ISSNs: 0044-2313

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The preparation and characterization of three new mixed ligand macrocyclic [Ni<sub>2</sub>L2(L′)]<sup>+</sup> complexes are described, where (L2)<sup>2–</sup> represents a supporting macrocyclic hexaaza‐bis(phenylsulfonato) ligand and L′ a tetrazolato ligand. The complexes [Ni<sub>2</sub>(L2)(CN<sub>4</sub>H)]BPh<sub>4</sub> (<bold>4</bold>), [Ni<sub>2</sub>(L2)(CN<sub>4</sub>Me)]BPh<sub>4</sub> (<bold>5</bold>), and [Ni<sub>2</sub>(L2)(CN<sub>4</sub>Ph)]BPh<sub>4</sub> (<bold>6</bold>) were synthesized by H<sub>2</sub>O<sub>2</sub> oxidation of the corresponding [Ni<sub>2</sub>(L1)(CN<sub>4</sub>H)]BPh<sub>4</sub> (<bold>1</bold>), [Ni<sub>2</sub>(L1)(CN<sub>4</sub>Me)]BPh<sub>4</sub> (<bold>2</bold>), and [Ni<sub>2</sub>(L1)(CN<sub>4</sub>Ph)]BPh<sub>4</sub> (<bold>3</bold>) complexes supported by the corresponding hexaaza‐bis(thiophenolate) macrocycle. The compounds were characterized by means of elemental analysis, mass spectrometry, IR, and UV/Vis spectroscopy. The crystal structures of compounds <bold>4</bold>–<bold>6</bold> show that the bridging thiophenolate functions in <bold>1</bold>–<bold>3</bold> are in all cases converted to μ<sub>1, 3</sub>‐bridging sulfonate groups to generate N<sub>3</sub>Ni(μ<sub>1, 3</sub>‐SO<sub>3</sub>R)<sub>2</sub>(μ‐RCN<sub>4</sub>)NiN<sub>3</sub> cores. The conversion to the phenylsulfonato groups is accompanied by a drastic increase of the Ni<bold>···</bold>Ni distances from 3.455(1) Å in <bold>1</bold>, 3.425(1) Å in <bold>2</bold>, and 3.443(1) Å [3.450(1) Å] in <bold>3</bold> to 4.2796(5) Å [4.3375(6) Å] in <bold>4</bold>, 4.3402(6) Å in <bold>5</bold>, and 4.2607(4) Å in <bold>6</bold>. Upon oxidation the magnetic properties are affected. In contrast to <bold>1</bold>–<bold>3</bold>, which exhibit an intramolecular ferromagnetic exchange interaction (<italic>S</italic> = 2 ground state), the spins of the nickel(II) (<italic>S</italic><sub>i</sub> = 1) ions in <bold>4</bold>–<bold>6</bold> are antiferromagnetically coupled, the coupling constants <italic>J</italic> being –1.39 cm<sup>–1</sup> (<bold>4</bold>), –1.43 cm<sup>–1</sup> (<bold>5</bold>), and –1.60 cm<sup>–1</sup> (<bold>6</bold>) (<bold><italic>H</italic></bold> = –2<italic>J<bold>S</bold></italic><sub>1</sub><bold><italic>S</italic></bold><sub>2</sub>) to yield a diamagnetic <italic>S</italic> = 0 ground state. DFT (density functional theory) calculations were carried out to substantiate the experimental results.</p> </abstract>