The synthesis of, and characterization of the dynamic processes occurring in Pd(ii) chelate complexes of 2-pyridyldiphenylphosphine

Jianke Liu; Chacko Jacob; Kelly J. Sheridan; Firas Al-Mosule; Brian T. Heaton; Jonathan A. Iggo; Mark Matthews; Jeremie Pelletier; Robin Whyman; Jamie F. Bickley; Alexander Steiner

doi:10.1039/b918162h

The synthesis of, and characterization of the dynamic processes occurring in Pd(ii) chelate complexes of 2-pyridyldiphenylphosphine

Jianke Liu, Chacko Jacob, Kelly J. Sheridan, Firas Al-Mosule, Brian T. Heaton, Jonathan A. Iggo, Mark Matthews, Jeremie Pelletier, Robin Whyman, Jamie F. Bickley, Alexander Steiner

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

25 Citations (Scopus)

Abstract

Pd(ii) complexes in which 2-pyridyldiphenylphosphine (Ph₂Ppy) chelates the Pd(ii) centre have been prepared and characterized by multinuclear NMR spectroscopy and by X-ray crystallographic analysis. trans- [Pd(κ¹-Ph₂Ppy)₂Cl₂] is transformed into [Pd(κ²-Ph₂Ppy)(κ¹- Ph₂Ppy)Cl]Cl by the addition of a few drops of methanol to dichloromethane solutions, and into [Pd(κ²-Ph ₂Ppy)(κ¹-Ph₂Ppy)Cl]X by addition of AgX or TlX, (X = BF₄^-, CF₃SO₃ ^- or MeSO₃^-). [Pd(κ¹-Ph ₂Ppy)₂(p-benzoquinone)] can be transformed into [Pd(κ²-Ph₂Ppy)(κ¹-Ph ₂Ppy)(MeSO₃)][MeSO₃] by the addition of two equivalents of MeSO₃H. Addition of further MeSO₃H affords [Pd(κ²-Ph₂Ppy)(κ¹-Ph ₂PpyH)(MeSO₃)][MeSO₃]₂. Addition of two equivalents of CF₃SO₃H, MeSO₃H or CF ₃CO₂H and two equivalents of Ph₂Ppy to [Pd(OAc)₂] in CH₂Cl₂ or CH₂Cl ₂-MeOH affords [Pd(κ²-Ph₂Ppy) (κ¹-Ph₂Ppy)X]X, (X = CF₃SO ₃^-, MeSO₃^- or CF₃CO ₂^-), however addition of two equivalents of HBF ₄·Et₂O affords a different complex, tentatively formulated as [Pd(κ²-Ph₂Ppy)₂]X ₂. Addition of excess acid results in the clean formation of [Pd(κ²-Ph₂Ppy)(κ¹-Ph ₂PpyH)(X)]X₂. In methanol, addition of MeSO₃H and three equivalents of Ph₂Ppy to [Pd(OAc)₂] affords [Pd(κ²-Ph₂Ppy)(κ¹-Ph ₂Ppy)₂][MeSO₃]₂ as the principal Pd-phosphine complex. The fluxional processes occuring in these complexes and in [Pd (κ¹-Ph₂Ppy)₃Cl]X, (X = Cl, OTf) and the potential for hemilability of the Ph₂Ppy ligand has been investigated by variable-temperature NMR. The activation entropy and enthalpy for the regiospecific fluxional processes occuring in [Pd(κ²- Ph₂Ppy)(κ¹-Ph₂Ppy)₂][MeSO ₃]₂ have been determined and are in the range -10 to -30 J mol^-1 K^-1 and ca. 30 kJ mol^-1 respectively, consistent with associative pathways being followed. The observed regioselectivities of the exchanges are attributed to the constraints imposed by microscopic reversibility and the small bite angle of the Ph₂Ppy ligand. X-Ray crystal structure determinations of trans-[Pd(κ¹- Ph₂Ppy)₂Cl₂], [Pd(κ²-Ph ₂Ppy)(κ¹-Ph₂Ppy)Cl][BF₄], [Pd(κ¹-Ph₂Ppy)₂(p-benzoquinone)], trans-[Pd(κ¹-Ph₂PpyH)₂Cl ₂][MeSO₃]₂, and [Pd(κ¹-Ph ₂Ppy)₃Cl](Cl) are reported. In [Pd(κ²- Ph₂Ppy)(κ¹-Ph₂Ppy)Cl][BF₄] a donor-acceptor interaction is seen between the pyridyl-N of the monodentate Ph₂Ppy ligand and the phosphorus of the chelating Ph₂Ppy resulting in a trigonal bipyramidal geometry at this phosphorus.

Original language	English
Pages (from-to)	7921-7935
Number of pages	15
Journal	Dalton Transactions
Volume	39
Issue number	34
DOIs	https://doi.org/10.1039/b918162h
Publication status	Published - 26 Jul 2010
Externally published	Yes

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10.1039/b918162h

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@article{8cc84ba16bc54489a208f4601a8107fb,

title = "The synthesis of, and characterization of the dynamic processes occurring in Pd(ii) chelate complexes of 2-pyridyldiphenylphosphine",

abstract = "Pd(ii) complexes in which 2-pyridyldiphenylphosphine (Ph2Ppy) chelates the Pd(ii) centre have been prepared and characterized by multinuclear NMR spectroscopy and by X-ray crystallographic analysis. trans- [Pd(κ1-Ph2Ppy)2Cl2] is transformed into [Pd(κ2-Ph2Ppy)(κ1- Ph2Ppy)Cl]Cl by the addition of a few drops of methanol to dichloromethane solutions, and into [Pd(κ2-Ph 2Ppy)(κ1-Ph2Ppy)Cl]X by addition of AgX or TlX, (X = BF4-, CF3SO3 - or MeSO3-). [Pd(κ1-Ph 2Ppy)2(p-benzoquinone)] can be transformed into [Pd(κ2-Ph2Ppy)(κ1-Ph 2Ppy)(MeSO3)][MeSO3] by the addition of two equivalents of MeSO3H. Addition of further MeSO3H affords [Pd(κ2-Ph2Ppy)(κ1-Ph 2PpyH)(MeSO3)][MeSO3]2. Addition of two equivalents of CF3SO3H, MeSO3H or CF 3CO2H and two equivalents of Ph2Ppy to [Pd(OAc)2] in CH2Cl2 or CH2Cl 2-MeOH affords [Pd(κ2-Ph2Ppy) (κ1-Ph2Ppy)X]X, (X = CF3SO 3-, MeSO3- or CF3CO 2-), however addition of two equivalents of HBF 4·Et2O affords a different complex, tentatively formulated as [Pd(κ2-Ph2Ppy)2]X 2. Addition of excess acid results in the clean formation of [Pd(κ2-Ph2Ppy)(κ1-Ph 2PpyH)(X)]X2. In methanol, addition of MeSO3H and three equivalents of Ph2Ppy to [Pd(OAc)2] affords [Pd(κ2-Ph2Ppy)(κ1-Ph 2Ppy)2][MeSO3]2 as the principal Pd-phosphine complex. The fluxional processes occuring in these complexes and in [Pd (κ1-Ph2Ppy)3Cl]X, (X = Cl, OTf) and the potential for hemilability of the Ph2Ppy ligand has been investigated by variable-temperature NMR. The activation entropy and enthalpy for the regiospecific fluxional processes occuring in [Pd(κ2- Ph2Ppy)(κ1-Ph2Ppy)2][MeSO 3]2 have been determined and are in the range -10 to -30 J mol-1 K-1 and ca. 30 kJ mol-1 respectively, consistent with associative pathways being followed. The observed regioselectivities of the exchanges are attributed to the constraints imposed by microscopic reversibility and the small bite angle of the Ph2Ppy ligand. X-Ray crystal structure determinations of trans-[Pd(κ1- Ph2Ppy)2Cl2], [Pd(κ2-Ph 2Ppy)(κ1-Ph2Ppy)Cl][BF4], [Pd(κ1-Ph2Ppy)2(p-benzoquinone)], trans-[Pd(κ1-Ph2PpyH)2Cl 2][MeSO3]2, and [Pd(κ1-Ph 2Ppy)3Cl](Cl) are reported. In [Pd(κ2- Ph2Ppy)(κ1-Ph2Ppy)Cl][BF4] a donor-acceptor interaction is seen between the pyridyl-N of the monodentate Ph2Ppy ligand and the phosphorus of the chelating Ph2Ppy resulting in a trigonal bipyramidal geometry at this phosphorus.",

author = "Jianke Liu and Chacko Jacob and Sheridan, {Kelly J.} and Firas Al-Mosule and Heaton, {Brian T.} and Iggo, {Jonathan A.} and Mark Matthews and Jeremie Pelletier and Robin Whyman and Bickley, {Jamie F.} and Alexander Steiner",

year = "2010",

month = jul,

day = "26",

doi = "10.1039/b918162h",

language = "English",

volume = "39",

pages = "7921--7935",

journal = "Dalton Transactions",

issn = "1477-9226",

publisher = "Royal Society of Chemistry",

number = "34",

}

TY - JOUR

T1 - The synthesis of, and characterization of the dynamic processes occurring in Pd(ii) chelate complexes of 2-pyridyldiphenylphosphine

AU - Liu, Jianke

AU - Jacob, Chacko

AU - Sheridan, Kelly J.

AU - Al-Mosule, Firas

AU - Heaton, Brian T.

AU - Iggo, Jonathan A.

AU - Matthews, Mark

AU - Pelletier, Jeremie

AU - Whyman, Robin

AU - Bickley, Jamie F.

AU - Steiner, Alexander

PY - 2010/7/26

Y1 - 2010/7/26

N2 - Pd(ii) complexes in which 2-pyridyldiphenylphosphine (Ph2Ppy) chelates the Pd(ii) centre have been prepared and characterized by multinuclear NMR spectroscopy and by X-ray crystallographic analysis. trans- [Pd(κ1-Ph2Ppy)2Cl2] is transformed into [Pd(κ2-Ph2Ppy)(κ1- Ph2Ppy)Cl]Cl by the addition of a few drops of methanol to dichloromethane solutions, and into [Pd(κ2-Ph 2Ppy)(κ1-Ph2Ppy)Cl]X by addition of AgX or TlX, (X = BF4-, CF3SO3 - or MeSO3-). [Pd(κ1-Ph 2Ppy)2(p-benzoquinone)] can be transformed into [Pd(κ2-Ph2Ppy)(κ1-Ph 2Ppy)(MeSO3)][MeSO3] by the addition of two equivalents of MeSO3H. Addition of further MeSO3H affords [Pd(κ2-Ph2Ppy)(κ1-Ph 2PpyH)(MeSO3)][MeSO3]2. Addition of two equivalents of CF3SO3H, MeSO3H or CF 3CO2H and two equivalents of Ph2Ppy to [Pd(OAc)2] in CH2Cl2 or CH2Cl 2-MeOH affords [Pd(κ2-Ph2Ppy) (κ1-Ph2Ppy)X]X, (X = CF3SO 3-, MeSO3- or CF3CO 2-), however addition of two equivalents of HBF 4·Et2O affords a different complex, tentatively formulated as [Pd(κ2-Ph2Ppy)2]X 2. Addition of excess acid results in the clean formation of [Pd(κ2-Ph2Ppy)(κ1-Ph 2PpyH)(X)]X2. In methanol, addition of MeSO3H and three equivalents of Ph2Ppy to [Pd(OAc)2] affords [Pd(κ2-Ph2Ppy)(κ1-Ph 2Ppy)2][MeSO3]2 as the principal Pd-phosphine complex. The fluxional processes occuring in these complexes and in [Pd (κ1-Ph2Ppy)3Cl]X, (X = Cl, OTf) and the potential for hemilability of the Ph2Ppy ligand has been investigated by variable-temperature NMR. The activation entropy and enthalpy for the regiospecific fluxional processes occuring in [Pd(κ2- Ph2Ppy)(κ1-Ph2Ppy)2][MeSO 3]2 have been determined and are in the range -10 to -30 J mol-1 K-1 and ca. 30 kJ mol-1 respectively, consistent with associative pathways being followed. The observed regioselectivities of the exchanges are attributed to the constraints imposed by microscopic reversibility and the small bite angle of the Ph2Ppy ligand. X-Ray crystal structure determinations of trans-[Pd(κ1- Ph2Ppy)2Cl2], [Pd(κ2-Ph 2Ppy)(κ1-Ph2Ppy)Cl][BF4], [Pd(κ1-Ph2Ppy)2(p-benzoquinone)], trans-[Pd(κ1-Ph2PpyH)2Cl 2][MeSO3]2, and [Pd(κ1-Ph 2Ppy)3Cl](Cl) are reported. In [Pd(κ2- Ph2Ppy)(κ1-Ph2Ppy)Cl][BF4] a donor-acceptor interaction is seen between the pyridyl-N of the monodentate Ph2Ppy ligand and the phosphorus of the chelating Ph2Ppy resulting in a trigonal bipyramidal geometry at this phosphorus.

AB - Pd(ii) complexes in which 2-pyridyldiphenylphosphine (Ph2Ppy) chelates the Pd(ii) centre have been prepared and characterized by multinuclear NMR spectroscopy and by X-ray crystallographic analysis. trans- [Pd(κ1-Ph2Ppy)2Cl2] is transformed into [Pd(κ2-Ph2Ppy)(κ1- Ph2Ppy)Cl]Cl by the addition of a few drops of methanol to dichloromethane solutions, and into [Pd(κ2-Ph 2Ppy)(κ1-Ph2Ppy)Cl]X by addition of AgX or TlX, (X = BF4-, CF3SO3 - or MeSO3-). [Pd(κ1-Ph 2Ppy)2(p-benzoquinone)] can be transformed into [Pd(κ2-Ph2Ppy)(κ1-Ph 2Ppy)(MeSO3)][MeSO3] by the addition of two equivalents of MeSO3H. Addition of further MeSO3H affords [Pd(κ2-Ph2Ppy)(κ1-Ph 2PpyH)(MeSO3)][MeSO3]2. Addition of two equivalents of CF3SO3H, MeSO3H or CF 3CO2H and two equivalents of Ph2Ppy to [Pd(OAc)2] in CH2Cl2 or CH2Cl 2-MeOH affords [Pd(κ2-Ph2Ppy) (κ1-Ph2Ppy)X]X, (X = CF3SO 3-, MeSO3- or CF3CO 2-), however addition of two equivalents of HBF 4·Et2O affords a different complex, tentatively formulated as [Pd(κ2-Ph2Ppy)2]X 2. Addition of excess acid results in the clean formation of [Pd(κ2-Ph2Ppy)(κ1-Ph 2PpyH)(X)]X2. In methanol, addition of MeSO3H and three equivalents of Ph2Ppy to [Pd(OAc)2] affords [Pd(κ2-Ph2Ppy)(κ1-Ph 2Ppy)2][MeSO3]2 as the principal Pd-phosphine complex. The fluxional processes occuring in these complexes and in [Pd (κ1-Ph2Ppy)3Cl]X, (X = Cl, OTf) and the potential for hemilability of the Ph2Ppy ligand has been investigated by variable-temperature NMR. The activation entropy and enthalpy for the regiospecific fluxional processes occuring in [Pd(κ2- Ph2Ppy)(κ1-Ph2Ppy)2][MeSO 3]2 have been determined and are in the range -10 to -30 J mol-1 K-1 and ca. 30 kJ mol-1 respectively, consistent with associative pathways being followed. The observed regioselectivities of the exchanges are attributed to the constraints imposed by microscopic reversibility and the small bite angle of the Ph2Ppy ligand. X-Ray crystal structure determinations of trans-[Pd(κ1- Ph2Ppy)2Cl2], [Pd(κ2-Ph 2Ppy)(κ1-Ph2Ppy)Cl][BF4], [Pd(κ1-Ph2Ppy)2(p-benzoquinone)], trans-[Pd(κ1-Ph2PpyH)2Cl 2][MeSO3]2, and [Pd(κ1-Ph 2Ppy)3Cl](Cl) are reported. In [Pd(κ2- Ph2Ppy)(κ1-Ph2Ppy)Cl][BF4] a donor-acceptor interaction is seen between the pyridyl-N of the monodentate Ph2Ppy ligand and the phosphorus of the chelating Ph2Ppy resulting in a trigonal bipyramidal geometry at this phosphorus.

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U2 - 10.1039/b918162h

DO - 10.1039/b918162h

M3 - Article

AN - SCOPUS:77955895443

SN - 1477-9226

VL - 39

SP - 7921

EP - 7935

JO - Dalton Transactions

JF - Dalton Transactions

IS - 34

ER -

The synthesis of, and characterization of the dynamic processes occurring in Pd(ii) chelate complexes of 2-pyridyldiphenylphosphine

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