Diiron(III) complexes of some relevance to the purple acid phosphatases

Shiping Yan; Xiangyang Pan; Lucille F. Taylor; Jian H. Zhang; Charles J. O'Connor; Doyle Britton; Oren P. Anderson; Lawrence Que

doi:10.1016/0020-1693(95)04884-7

Diiron(III) complexes of some relevance to the purple acid phosphatases

Shiping Yan, Xiangyang Pan, Lucille F. Taylor, Jian H. Zhang, Charles J. O'Connor, Doyle Britton, Oren P. Anderson, Lawrence Que

Chemistry (Twin Cities)

Research output: Contribution to journal › Article › peer-review

30 Scopus citations

Abstract

Three diiron(III) complexes of the tetradentate tripodal ligand N-(0-hydroxybenzyl)-N,N-bis(2-pyridylmethyl)amine (HDP), [Fe₂(HDP)₂O(O₂CPh)]BPh₄ (1), [Fe₂(HDP)₂O{O₂P(OPh)₂}]BPh ₄ (2), and [Fe₂(HDP)₂{O₂P(OPh)₂} ₂](BPh₄)₂ (3), have been synthesized as models for the active site of the purple acid phosphatases. Single crystals of 1 (P2₁2₁2₁, a = 17.728(3) Å, b = 18.204(4) Å, c = 19.383(4) Å, Z = 4, V= 6255 Å³) and 3 (P1, a = 14.316(11) Å, b = 15.136(17) Å, c = 13.303(6) Å, α = 97.04(7)°, β = 104.48(5)°, γ = 115.51(8)°, Z = 1, V = 2430(6) Å³) were obtained and subjected to X-ray diffraction analysis. Complex 1 has a (μ-oxo)(μ-benzoato)diiron(III) core, while complex 3 has a bis(μ-phosphato)diiron(III) core, the tetradentate HDP completing the coordination sphere about each iron center in both complexes. Due to differences in their core structures, the Fe-Fe separations in 1 and 3 are 3.217(11) Å and 4.819(1) Å, respectively. Complex 2 is presumed to have a structure analogous to 1 with phosphate replacing the benzoate bridge. Both 1 and 2 exhibit strong antiferromagnetic coupling due to the presence of the oxo bridge (J = -111 and -96 cm^-1, respectively; H =-2JS₁^-·S₂). Interestingly, the iron(III) centers in 3 are not coupled at all; 3 exhibits Curie behavior throughout the entire temperature range studied (6-300 K) with a magnetic moment commensurate with two high-spin iron(III) centers. The three complexes exhibit visible absorption maxima at 522, 516, and 605 nm, respectively, arising from phenolate-to-iron(III) charge transfer transitions. The shifts in the λ_max values can be rationalized on the basis of the Lewis acidities of the respective iron(III) centers. These are compared with those of the purple acid phosphatases.

Original language	English (US)
Pages (from-to)	1-8
Number of pages	8
Journal	Inorganica Chimica Acta
Volume	243
Issue number	1-2
DOIs	https://doi.org/10.1016/0020-1693(95)04884-7
State	Published - Feb 29 1996

Bibliographical note

Funding Information:
This work was supported by grants from the National Institutes of Health (GM-38767, L.Q.; GM-30306, O.P.A.) and the National Science Foundation (for the purchase of the X-ray equipment at Colorado State University).

Keywords

Dinuclear complexes
Iron(III) complexes
Purple acid phosphatases

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10.1016/0020-1693(95)04884-7

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@article{6380481a260b48dab2f3b23e6eff4a72,

title = "Diiron(III) complexes of some relevance to the purple acid phosphatases",

abstract = "Three diiron(III) complexes of the tetradentate tripodal ligand N-(0-hydroxybenzyl)-N,N-bis(2-pyridylmethyl)amine (HDP), [Fe2(HDP)2O(O2CPh)]BPh4 (1), [Fe2(HDP)2O{O2P(OPh)2}]BPh 4 (2), and [Fe2(HDP)2{O2P(OPh)2} 2](BPh4)2 (3), have been synthesized as models for the active site of the purple acid phosphatases. Single crystals of 1 (P212121, a = 17.728(3) {\AA}, b = 18.204(4) {\AA}, c = 19.383(4) {\AA}, Z = 4, V= 6255 {\AA}3) and 3 (P1, a = 14.316(11) {\AA}, b = 15.136(17) {\AA}, c = 13.303(6) {\AA}, α = 97.04(7)°, β = 104.48(5)°, γ = 115.51(8)°, Z = 1, V = 2430(6) {\AA}3) were obtained and subjected to X-ray diffraction analysis. Complex 1 has a (μ-oxo)(μ-benzoato)diiron(III) core, while complex 3 has a bis(μ-phosphato)diiron(III) core, the tetradentate HDP completing the coordination sphere about each iron center in both complexes. Due to differences in their core structures, the Fe-Fe separations in 1 and 3 are 3.217(11) {\AA} and 4.819(1) {\AA}, respectively. Complex 2 is presumed to have a structure analogous to 1 with phosphate replacing the benzoate bridge. Both 1 and 2 exhibit strong antiferromagnetic coupling due to the presence of the oxo bridge (J = -111 and -96 cm-1, respectively; H =-2JS1-·S2). Interestingly, the iron(III) centers in 3 are not coupled at all; 3 exhibits Curie behavior throughout the entire temperature range studied (6-300 K) with a magnetic moment commensurate with two high-spin iron(III) centers. The three complexes exhibit visible absorption maxima at 522, 516, and 605 nm, respectively, arising from phenolate-to-iron(III) charge transfer transitions. The shifts in the λmax values can be rationalized on the basis of the Lewis acidities of the respective iron(III) centers. These are compared with those of the purple acid phosphatases.",

keywords = "Dinuclear complexes, Iron(III) complexes, Purple acid phosphatases",

author = "Shiping Yan and Xiangyang Pan and Taylor, {Lucille F.} and Zhang, {Jian H.} and O'Connor, {Charles J.} and Doyle Britton and Anderson, {Oren P.} and Lawrence Que",

note = "Funding Information: This work was supported by grants from the National Institutes of Health (GM-38767, L.Q.; GM-30306, O.P.A.) and the National Science Foundation (for the purchase of the X-ray equipment at Colorado State University).",

year = "1996",

month = feb,

day = "29",

doi = "10.1016/0020-1693(95)04884-7",

language = "English (US)",

volume = "243",

pages = "1--8",

journal = "Inorganica Chimica Acta",

issn = "0020-1693",

publisher = "Elsevier B.V.",

number = "1-2",

}

TY - JOUR

T1 - Diiron(III) complexes of some relevance to the purple acid phosphatases

AU - Yan, Shiping

AU - Pan, Xiangyang

AU - Taylor, Lucille F.

AU - Zhang, Jian H.

AU - O'Connor, Charles J.

AU - Britton, Doyle

AU - Anderson, Oren P.

AU - Que, Lawrence

N1 - Funding Information: This work was supported by grants from the National Institutes of Health (GM-38767, L.Q.; GM-30306, O.P.A.) and the National Science Foundation (for the purchase of the X-ray equipment at Colorado State University).

PY - 1996/2/29

Y1 - 1996/2/29

N2 - Three diiron(III) complexes of the tetradentate tripodal ligand N-(0-hydroxybenzyl)-N,N-bis(2-pyridylmethyl)amine (HDP), [Fe2(HDP)2O(O2CPh)]BPh4 (1), [Fe2(HDP)2O{O2P(OPh)2}]BPh 4 (2), and [Fe2(HDP)2{O2P(OPh)2} 2](BPh4)2 (3), have been synthesized as models for the active site of the purple acid phosphatases. Single crystals of 1 (P212121, a = 17.728(3) Å, b = 18.204(4) Å, c = 19.383(4) Å, Z = 4, V= 6255 Å3) and 3 (P1, a = 14.316(11) Å, b = 15.136(17) Å, c = 13.303(6) Å, α = 97.04(7)°, β = 104.48(5)°, γ = 115.51(8)°, Z = 1, V = 2430(6) Å3) were obtained and subjected to X-ray diffraction analysis. Complex 1 has a (μ-oxo)(μ-benzoato)diiron(III) core, while complex 3 has a bis(μ-phosphato)diiron(III) core, the tetradentate HDP completing the coordination sphere about each iron center in both complexes. Due to differences in their core structures, the Fe-Fe separations in 1 and 3 are 3.217(11) Å and 4.819(1) Å, respectively. Complex 2 is presumed to have a structure analogous to 1 with phosphate replacing the benzoate bridge. Both 1 and 2 exhibit strong antiferromagnetic coupling due to the presence of the oxo bridge (J = -111 and -96 cm-1, respectively; H =-2JS1-·S2). Interestingly, the iron(III) centers in 3 are not coupled at all; 3 exhibits Curie behavior throughout the entire temperature range studied (6-300 K) with a magnetic moment commensurate with two high-spin iron(III) centers. The three complexes exhibit visible absorption maxima at 522, 516, and 605 nm, respectively, arising from phenolate-to-iron(III) charge transfer transitions. The shifts in the λmax values can be rationalized on the basis of the Lewis acidities of the respective iron(III) centers. These are compared with those of the purple acid phosphatases.

AB - Three diiron(III) complexes of the tetradentate tripodal ligand N-(0-hydroxybenzyl)-N,N-bis(2-pyridylmethyl)amine (HDP), [Fe2(HDP)2O(O2CPh)]BPh4 (1), [Fe2(HDP)2O{O2P(OPh)2}]BPh 4 (2), and [Fe2(HDP)2{O2P(OPh)2} 2](BPh4)2 (3), have been synthesized as models for the active site of the purple acid phosphatases. Single crystals of 1 (P212121, a = 17.728(3) Å, b = 18.204(4) Å, c = 19.383(4) Å, Z = 4, V= 6255 Å3) and 3 (P1, a = 14.316(11) Å, b = 15.136(17) Å, c = 13.303(6) Å, α = 97.04(7)°, β = 104.48(5)°, γ = 115.51(8)°, Z = 1, V = 2430(6) Å3) were obtained and subjected to X-ray diffraction analysis. Complex 1 has a (μ-oxo)(μ-benzoato)diiron(III) core, while complex 3 has a bis(μ-phosphato)diiron(III) core, the tetradentate HDP completing the coordination sphere about each iron center in both complexes. Due to differences in their core structures, the Fe-Fe separations in 1 and 3 are 3.217(11) Å and 4.819(1) Å, respectively. Complex 2 is presumed to have a structure analogous to 1 with phosphate replacing the benzoate bridge. Both 1 and 2 exhibit strong antiferromagnetic coupling due to the presence of the oxo bridge (J = -111 and -96 cm-1, respectively; H =-2JS1-·S2). Interestingly, the iron(III) centers in 3 are not coupled at all; 3 exhibits Curie behavior throughout the entire temperature range studied (6-300 K) with a magnetic moment commensurate with two high-spin iron(III) centers. The three complexes exhibit visible absorption maxima at 522, 516, and 605 nm, respectively, arising from phenolate-to-iron(III) charge transfer transitions. The shifts in the λmax values can be rationalized on the basis of the Lewis acidities of the respective iron(III) centers. These are compared with those of the purple acid phosphatases.

KW - Dinuclear complexes

KW - Iron(III) complexes

KW - Purple acid phosphatases

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UR - http://www.scopus.com/inward/citedby.url?scp=0003142699&partnerID=8YFLogxK

U2 - 10.1016/0020-1693(95)04884-7

DO - 10.1016/0020-1693(95)04884-7

M3 - Article

AN - SCOPUS:0003142699

SN - 0020-1693

VL - 243

SP - 1

EP - 8

JO - Inorganica Chimica Acta

JF - Inorganica Chimica Acta

IS - 1-2

ER -

Diiron(III) complexes of some relevance to the purple acid phosphatases

Abstract

Bibliographical note

Keywords

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