Pyrophosphate-mediated magnetic interactions in Cu(II) coordination complexes

Nadia Marino, Oluwatayo F. Ikotun, Miguel Julve, Francesc Lloret, Juan Cano, Robert Patrick Doyle

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

The reaction in water of Cu(NO3)2·2.5H 2O with 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), or 1,10-phenanthroline-5-amine (phenam), and sodium pyrophosphate (Na 4P2O7), at various pHs, afforded three new copper(II)-pyrophosphate complexes, namely, {[Cu(bipy)(cis-H2P 2O7)]2}·3H2O (1a), {[Cu(phen)(H2O)]4(HP2O7) 2}(ClO4)2·4H2O (2), and {[Cu2(phenam)2(P2O7)] 2·25H2O}n (3). A solvent free crystalline phase of 1a was also isolated with formula {[Cu(bipy)(trans-H 2P2O7)]2} (1b), which can be regarded as a pseudo-polymorph of 1a. Single crystal X-ray analyses revealed these compounds to have uncommon molecular architectures, with 3 being an unprecedented pyrophosphate-containing two-dimensional (2D) polymer. Compounds 1a/1b and 2 are discrete di- and tetra-nuclear complexes, respectively. The cationic {[Cu(phen)(H2O)]4(HP2O 7)2}2+ unit in 2 presents a unique quasi-flat structure, held together by solely in-plane pyrophosphate bridging modes (short Oeq-P-Oeq and long Oeq-P-O-P-Oeq pathways), a coordination arrangement also not previously reported. A different tetranuclear copper(II)-pyrophosphate arrangement is found in 3, with two classically bridged dimers (Oeq-P-Oeq pathway) joined together by auxiliary equatorial-axial μ-O pyrophosphate bridges. Here, the bidimensionality is reached through bridging phenam ligands, which provide further inter-"tetramer" metal-metal connections [(N,N′) eq-(N″)ax pathway], leading to the formation of an expanded covalent network based on the [Cu2(phenam) 2(P2O7)]2 moiety. Variable-temperature magnetic susceptibility measurements on polycrystalline samples of 2 and 3 revealed net antiferromagnetic coupling between metal centers with J2a = -7.9(2) cm-1, J2b = -46.9(3) cm-1, J2c = 0 cm-1 in 2 (H = -J 2a[SCu(1)·SCu(2) + S Cu(1a)·SCu(2a)] - J2b[S Cu(1)·SCu(2a) + SCu(1a)·S Cu(2)] - J2cSCu(2)·SCu(2a)), and J3a = -87.9(2) cm-1, J3b = -5(1) cm -1 and J3c = +5(3) cm-1 in 3 (H = -J 3a[SCu(1)·SCu(2) + S Cu(1a)·SCu(2a)] - J3b[S Cu(1)·SCu(2a) + SCu(1a)·S Cu(2)] - J3cSCu(2)·SCu(2a)). For 1a, a net ferromagnetic coupling is observed with J1a = +0.86(1) cm-1 (H = -J SA·SB + S A·D·SB + βH (gASA + gBSB). This is the first example of ferromagnetic coupling in pyrophosphate-complexes reported to date. A structure-function correlation study focusing on magnetic exchange across the observed diverse pyrophosphate-bridges is described with density functional theory (DFT) calculations included to support the stated observations.

Original languageEnglish (US)
Pages (from-to)378-389
Number of pages12
JournalInorganic Chemistry
Volume50
Issue number1
DOIs
StatePublished - Jan 3 2011

Fingerprint

Coordination Complexes
amines
Amines
interactions
metals
Phenanthrolines
Metals
copper
Copper
dimers
sodium
density functional theory
magnetic permeability
ligands
diphosphoric acid
Polymorphism
Magnetic susceptibility
single crystals
polymers
Dimers

ASJC Scopus subject areas

  • Inorganic Chemistry
  • Physical and Theoretical Chemistry

Cite this

Pyrophosphate-mediated magnetic interactions in Cu(II) coordination complexes. / Marino, Nadia; Ikotun, Oluwatayo F.; Julve, Miguel; Lloret, Francesc; Cano, Juan; Doyle, Robert Patrick.

In: Inorganic Chemistry, Vol. 50, No. 1, 03.01.2011, p. 378-389.

Research output: Contribution to journalArticle

Marino, Nadia ; Ikotun, Oluwatayo F. ; Julve, Miguel ; Lloret, Francesc ; Cano, Juan ; Doyle, Robert Patrick. / Pyrophosphate-mediated magnetic interactions in Cu(II) coordination complexes. In: Inorganic Chemistry. 2011 ; Vol. 50, No. 1. pp. 378-389.
@article{eab8e3e62af84fc5abaafad2d0e2b06a,
title = "Pyrophosphate-mediated magnetic interactions in Cu(II) coordination complexes",
abstract = "The reaction in water of Cu(NO3)2·2.5H 2O with 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), or 1,10-phenanthroline-5-amine (phenam), and sodium pyrophosphate (Na 4P2O7), at various pHs, afforded three new copper(II)-pyrophosphate complexes, namely, {[Cu(bipy)(cis-H2P 2O7)]2}·3H2O (1a), {[Cu(phen)(H2O)]4(HP2O7) 2}(ClO4)2·4H2O (2), and {[Cu2(phenam)2(P2O7)] 2·25H2O}n (3). A solvent free crystalline phase of 1a was also isolated with formula {[Cu(bipy)(trans-H 2P2O7)]2} (1b), which can be regarded as a pseudo-polymorph of 1a. Single crystal X-ray analyses revealed these compounds to have uncommon molecular architectures, with 3 being an unprecedented pyrophosphate-containing two-dimensional (2D) polymer. Compounds 1a/1b and 2 are discrete di- and tetra-nuclear complexes, respectively. The cationic {[Cu(phen)(H2O)]4(HP2O 7)2}2+ unit in 2 presents a unique quasi-flat structure, held together by solely in-plane pyrophosphate bridging modes (short Oeq-P-Oeq and long Oeq-P-O-P-Oeq pathways), a coordination arrangement also not previously reported. A different tetranuclear copper(II)-pyrophosphate arrangement is found in 3, with two classically bridged dimers (Oeq-P-Oeq pathway) joined together by auxiliary equatorial-axial μ-O pyrophosphate bridges. Here, the bidimensionality is reached through bridging phenam ligands, which provide further inter-{"}tetramer{"} metal-metal connections [(N,N′) eq-(N″)ax pathway], leading to the formation of an expanded covalent network based on the [Cu2(phenam) 2(P2O7)]2 moiety. Variable-temperature magnetic susceptibility measurements on polycrystalline samples of 2 and 3 revealed net antiferromagnetic coupling between metal centers with J2a = -7.9(2) cm-1, J2b = -46.9(3) cm-1, J2c = 0 cm-1 in 2 (H = -J 2a[SCu(1)·SCu(2) + S Cu(1a)·SCu(2a)] - J2b[S Cu(1)·SCu(2a) + SCu(1a)·S Cu(2)] - J2cSCu(2)·SCu(2a)), and J3a = -87.9(2) cm-1, J3b = -5(1) cm -1 and J3c = +5(3) cm-1 in 3 (H = -J 3a[SCu(1)·SCu(2) + S Cu(1a)·SCu(2a)] - J3b[S Cu(1)·SCu(2a) + SCu(1a)·S Cu(2)] - J3cSCu(2)·SCu(2a)). For 1a, a net ferromagnetic coupling is observed with J1a = +0.86(1) cm-1 (H = -J SA·SB + S A·D·SB + βH (gASA + gBSB). This is the first example of ferromagnetic coupling in pyrophosphate-complexes reported to date. A structure-function correlation study focusing on magnetic exchange across the observed diverse pyrophosphate-bridges is described with density functional theory (DFT) calculations included to support the stated observations.",
author = "Nadia Marino and Ikotun, {Oluwatayo F.} and Miguel Julve and Francesc Lloret and Juan Cano and Doyle, {Robert Patrick}",
year = "2011",
month = "1",
day = "3",
doi = "10.1021/ic1020884",
language = "English (US)",
volume = "50",
pages = "378--389",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "1",

}

TY - JOUR

T1 - Pyrophosphate-mediated magnetic interactions in Cu(II) coordination complexes

AU - Marino, Nadia

AU - Ikotun, Oluwatayo F.

AU - Julve, Miguel

AU - Lloret, Francesc

AU - Cano, Juan

AU - Doyle, Robert Patrick

PY - 2011/1/3

Y1 - 2011/1/3

N2 - The reaction in water of Cu(NO3)2·2.5H 2O with 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), or 1,10-phenanthroline-5-amine (phenam), and sodium pyrophosphate (Na 4P2O7), at various pHs, afforded three new copper(II)-pyrophosphate complexes, namely, {[Cu(bipy)(cis-H2P 2O7)]2}·3H2O (1a), {[Cu(phen)(H2O)]4(HP2O7) 2}(ClO4)2·4H2O (2), and {[Cu2(phenam)2(P2O7)] 2·25H2O}n (3). A solvent free crystalline phase of 1a was also isolated with formula {[Cu(bipy)(trans-H 2P2O7)]2} (1b), which can be regarded as a pseudo-polymorph of 1a. Single crystal X-ray analyses revealed these compounds to have uncommon molecular architectures, with 3 being an unprecedented pyrophosphate-containing two-dimensional (2D) polymer. Compounds 1a/1b and 2 are discrete di- and tetra-nuclear complexes, respectively. The cationic {[Cu(phen)(H2O)]4(HP2O 7)2}2+ unit in 2 presents a unique quasi-flat structure, held together by solely in-plane pyrophosphate bridging modes (short Oeq-P-Oeq and long Oeq-P-O-P-Oeq pathways), a coordination arrangement also not previously reported. A different tetranuclear copper(II)-pyrophosphate arrangement is found in 3, with two classically bridged dimers (Oeq-P-Oeq pathway) joined together by auxiliary equatorial-axial μ-O pyrophosphate bridges. Here, the bidimensionality is reached through bridging phenam ligands, which provide further inter-"tetramer" metal-metal connections [(N,N′) eq-(N″)ax pathway], leading to the formation of an expanded covalent network based on the [Cu2(phenam) 2(P2O7)]2 moiety. Variable-temperature magnetic susceptibility measurements on polycrystalline samples of 2 and 3 revealed net antiferromagnetic coupling between metal centers with J2a = -7.9(2) cm-1, J2b = -46.9(3) cm-1, J2c = 0 cm-1 in 2 (H = -J 2a[SCu(1)·SCu(2) + S Cu(1a)·SCu(2a)] - J2b[S Cu(1)·SCu(2a) + SCu(1a)·S Cu(2)] - J2cSCu(2)·SCu(2a)), and J3a = -87.9(2) cm-1, J3b = -5(1) cm -1 and J3c = +5(3) cm-1 in 3 (H = -J 3a[SCu(1)·SCu(2) + S Cu(1a)·SCu(2a)] - J3b[S Cu(1)·SCu(2a) + SCu(1a)·S Cu(2)] - J3cSCu(2)·SCu(2a)). For 1a, a net ferromagnetic coupling is observed with J1a = +0.86(1) cm-1 (H = -J SA·SB + S A·D·SB + βH (gASA + gBSB). This is the first example of ferromagnetic coupling in pyrophosphate-complexes reported to date. A structure-function correlation study focusing on magnetic exchange across the observed diverse pyrophosphate-bridges is described with density functional theory (DFT) calculations included to support the stated observations.

AB - The reaction in water of Cu(NO3)2·2.5H 2O with 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), or 1,10-phenanthroline-5-amine (phenam), and sodium pyrophosphate (Na 4P2O7), at various pHs, afforded three new copper(II)-pyrophosphate complexes, namely, {[Cu(bipy)(cis-H2P 2O7)]2}·3H2O (1a), {[Cu(phen)(H2O)]4(HP2O7) 2}(ClO4)2·4H2O (2), and {[Cu2(phenam)2(P2O7)] 2·25H2O}n (3). A solvent free crystalline phase of 1a was also isolated with formula {[Cu(bipy)(trans-H 2P2O7)]2} (1b), which can be regarded as a pseudo-polymorph of 1a. Single crystal X-ray analyses revealed these compounds to have uncommon molecular architectures, with 3 being an unprecedented pyrophosphate-containing two-dimensional (2D) polymer. Compounds 1a/1b and 2 are discrete di- and tetra-nuclear complexes, respectively. The cationic {[Cu(phen)(H2O)]4(HP2O 7)2}2+ unit in 2 presents a unique quasi-flat structure, held together by solely in-plane pyrophosphate bridging modes (short Oeq-P-Oeq and long Oeq-P-O-P-Oeq pathways), a coordination arrangement also not previously reported. A different tetranuclear copper(II)-pyrophosphate arrangement is found in 3, with two classically bridged dimers (Oeq-P-Oeq pathway) joined together by auxiliary equatorial-axial μ-O pyrophosphate bridges. Here, the bidimensionality is reached through bridging phenam ligands, which provide further inter-"tetramer" metal-metal connections [(N,N′) eq-(N″)ax pathway], leading to the formation of an expanded covalent network based on the [Cu2(phenam) 2(P2O7)]2 moiety. Variable-temperature magnetic susceptibility measurements on polycrystalline samples of 2 and 3 revealed net antiferromagnetic coupling between metal centers with J2a = -7.9(2) cm-1, J2b = -46.9(3) cm-1, J2c = 0 cm-1 in 2 (H = -J 2a[SCu(1)·SCu(2) + S Cu(1a)·SCu(2a)] - J2b[S Cu(1)·SCu(2a) + SCu(1a)·S Cu(2)] - J2cSCu(2)·SCu(2a)), and J3a = -87.9(2) cm-1, J3b = -5(1) cm -1 and J3c = +5(3) cm-1 in 3 (H = -J 3a[SCu(1)·SCu(2) + S Cu(1a)·SCu(2a)] - J3b[S Cu(1)·SCu(2a) + SCu(1a)·S Cu(2)] - J3cSCu(2)·SCu(2a)). For 1a, a net ferromagnetic coupling is observed with J1a = +0.86(1) cm-1 (H = -J SA·SB + S A·D·SB + βH (gASA + gBSB). This is the first example of ferromagnetic coupling in pyrophosphate-complexes reported to date. A structure-function correlation study focusing on magnetic exchange across the observed diverse pyrophosphate-bridges is described with density functional theory (DFT) calculations included to support the stated observations.

UR - http://www.scopus.com/inward/record.url?scp=78650709712&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78650709712&partnerID=8YFLogxK

U2 - 10.1021/ic1020884

DO - 10.1021/ic1020884

M3 - Article

C2 - 21114311

AN - SCOPUS:78650709712

VL - 50

SP - 378

EP - 389

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 1

ER -