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Magneto-Structural Studies on Two Bis-μ-Methoxido-Bridged Dicopper(II) Complexes Supported by Subtly Different m-Xylyl-Based Terminal N3 Donor Binucleating Ligands

Singh, Ravindra ; Lloret, Francesc ; Nordlander, Ebbe LU and Mukherjee, Rabindranath (2025) In Zeitschrift fur Anorganische und Allgemeine Chemie
Abstract

Reactions of LXYL17 or LXYL18 (LXYL17 = α,α′-bis[((1-methyl-2-benzimidazolyl)methyl)-N-(6-methyl-2-pyridylmethyl)-amino]-m-xylene; LXYL18 = α,α′-bis[((1-methyl-2-benzimi-dazolyl)-methyl)-N-(2-pyridylethyl)-amino]-m-xylene) with [Cu(MeCN)4](ClO4) in CH2Cl2 at 298 K, subsequent exposure to dioxygen, and work-up from MeCN–MeOH, led to [CuII2(LXYL17)(μ-OMe)2](ClO4)2•0·5H2O (1) and [CuII2(L XYL18)(μ-OMe)2](ClO4)2•0.5MeCN (2). Structural characterization revealed their bis(methoxido)-bridged binuclear copper(II)... (More)

Reactions of LXYL17 or LXYL18 (LXYL17 = α,α′-bis[((1-methyl-2-benzimidazolyl)methyl)-N-(6-methyl-2-pyridylmethyl)-amino]-m-xylene; LXYL18 = α,α′-bis[((1-methyl-2-benzimi-dazolyl)-methyl)-N-(2-pyridylethyl)-amino]-m-xylene) with [Cu(MeCN)4](ClO4) in CH2Cl2 at 298 K, subsequent exposure to dioxygen, and work-up from MeCN–MeOH, led to [CuII2(LXYL17)(μ-OMe)2](ClO4)2•0·5H2O (1) and [CuII2(L XYL18)(μ-OMe)2](ClO4)2•0.5MeCN (2). Structural characterization revealed their bis(methoxido)-bridged binuclear copper(II) structure. The well-known ring-hydroxylation of the xylyl-spacer has not been observed here. In both 1 and 2, each copper(II) center is terminally coordinated by a common N-methyl-benzimidazolyl nitrogen and a tertiary amine nitrogen; in 1, an additional terminal coordination is provided by a 6-methyl-2-pyridylmethyl nitrogen, generating a five-membered and in 2 it is by a 2-pyridylethyl nitrogen, generating a six-membered chelate ring. The binuclear copper(II) complexes have Cu…Cu separation of 3.0239(16) Å (1) and 3.0022(17) Å (2). The geometry around the two Cu(II) centers is almost ideal square-pyramidal in 1 (τ values: 0.05 and 0.015) and slightly distorted in 2 (τ values: 0.23 and 0.243). Magnetic susceptibility measurements (100–300 K) on 1 and 2 reveal strong antiferromagnetic coupling J = –916(10) cm–1 for 1 and J = –820(10) cm–1 for 2. The differential magnetic coupling is fine-tuned by structural differences exerted by two subtly different non-Schiff base m-xylyl-based terminal N3 ligands.

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publication status
epub
subject
keywords
crystal structures, di-μ-methoxido-bridged dicopper(II), m-xylyl-based binucleating ligands, magnetism
in
Zeitschrift fur Anorganische und Allgemeine Chemie
publisher
Wiley-VCH Verlag
external identifiers
  • scopus:105014923526
ISSN
0044-2313
DOI
10.1002/zaac.202500130
language
English
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yes
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ac26ae3e-2451-48c2-9b17-4a37806bab5a
date added to LUP
2025-11-14 15:17:13
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2025-11-14 15:17:49
@article{ac26ae3e-2451-48c2-9b17-4a37806bab5a,
  abstract     = {{<p>Reactions of L<sup>XYL17</sup> or L<sup>XYL18</sup> (L<sup>XYL17</sup> = α,α′-bis[((1-methyl-2-benzimidazolyl)methyl)-N-(6-methyl-2-pyridylmethyl)-amino]-m-xylene; L<sup>XYL18</sup> = α,α′-bis[((1-methyl-2-benzimi-dazolyl)-methyl)-N-(2-pyridylethyl)-amino]-m-xylene) with [Cu(MeCN)<sub>4</sub>](ClO<sub>4</sub>) in CH<sub>2</sub>Cl<sub>2</sub> at 298 K, subsequent exposure to dioxygen, and work-up from MeCN–MeOH, led to [Cu<sup>II</sup><sub>2</sub>(L<sup>XYL17</sup>)(μ-OMe)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub>•0·5H<sub>2</sub>O (1) and [Cu<sup>II</sup><sub>2</sub>(L <sup>XYL18</sup>)(μ-OMe)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub>•0.5MeCN (2). Structural characterization revealed their bis(methoxido)-bridged binuclear copper(II) structure. The well-known ring-hydroxylation of the xylyl-spacer has not been observed here. In both 1 and 2, each copper(II) center is terminally coordinated by a common N-methyl-benzimidazolyl nitrogen and a tertiary amine nitrogen; in 1, an additional terminal coordination is provided by a 6-methyl-2-pyridylmethyl nitrogen, generating a five-membered and in 2 it is by a 2-pyridylethyl nitrogen, generating a six-membered chelate ring. The binuclear copper(II) complexes have Cu<sup>…</sup>Cu separation of 3.0239(16) Å (1) and 3.0022(17) Å (2). The geometry around the two Cu(II) centers is almost ideal square-pyramidal in 1 (τ values: 0.05 and 0.015) and slightly distorted in 2 (τ values: 0.23 and 0.243). Magnetic susceptibility measurements (100–300 K) on 1 and 2 reveal strong antiferromagnetic coupling J = –916(10) cm<sup>–1</sup> for 1 and J = –820(10) cm<sup>–1</sup> for 2. The differential magnetic coupling is fine-tuned by structural differences exerted by two subtly different non-Schiff base m-xylyl-based terminal N<sub>3</sub> ligands.</p>}},
  author       = {{Singh, Ravindra and Lloret, Francesc and Nordlander, Ebbe and Mukherjee, Rabindranath}},
  issn         = {{0044-2313}},
  keywords     = {{crystal structures; di-μ-methoxido-bridged dicopper(II); m-xylyl-based binucleating ligands; magnetism}},
  language     = {{eng}},
  publisher    = {{Wiley-VCH Verlag}},
  series       = {{Zeitschrift fur Anorganische und Allgemeine Chemie}},
  title        = {{Magneto-Structural Studies on Two Bis-μ-Methoxido-Bridged Dicopper(II) Complexes Supported by Subtly Different m-Xylyl-Based Terminal N<sub>3</sub> Donor Binucleating Ligands}},
  url          = {{http://dx.doi.org/10.1002/zaac.202500130}},
  doi          = {{10.1002/zaac.202500130}},
  year         = {{2025}},
}