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Speaker : Po-Yuan Chung Supervisor : Prof. Shuchun Joyce Yu Date : 2008/06/16 PowerPoint PPT Presentation


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17 e -. Synthesis and Characterization of the 17-Valence Electron Tris(2-pyridyl)Phosphine Oxide Ligated Chromium Nitrosyl Complex. Speaker : Po-Yuan Chung Supervisor : Prof. Shuchun Joyce Yu Date : 2008/06/16. Outline. Introduction - Discovery of 17-e - compounds

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Speaker : Po-Yuan Chung Supervisor : Prof. Shuchun Joyce Yu Date : 2008/06/16

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17 e-

Synthesis and Characterization of the 17-Valence Electron Tris(2-pyridyl)Phosphine Oxide Ligated Chromium Nitrosyl Complex.

Speaker:Po-Yuan Chung

Supervisor : Prof. Shuchun Joyce Yu

Date:2008/06/16


Outline

  • Introduction

    - Discovery of 17-e- compounds

    - Classification of 17-e- compounds

    - Application

  • Experimental section

    - [OP(2-py)3M(CO)3-n(NO)n](BF4)n M = Cr, Mo, W ; n = 0~2

    - [OP(2-py)3Cr(MeCN)2(NO)](BF4)2

    - Analyze the compounds of 16, 17 and 18 electrons

  • Conclusions

    - Plausible formation pathways


Paramagnetic Organochromium Complexeswith 17 Valence Electrons

17 e-

18 e-

Strametz, H.; Fischer, E. O. J. Organomet. Chem.1967, 10, 323


17-Valence Electron Organochromium Complexes

(1) Hexacoordinated Species

[CrL6]+

Michael C. Baird, Chem. Rev. 1988.88. 1217-1227


17-Valence Electron Organochromium Complexes

(2) Cyclopentadienyl Species

CpCrL3

MICHAEL C. BAIRD, Chem. Rev. 1988.88. 1217-1227


17-Valence Electron Organochromium Complexes

(3) Nitrosyl Species

[Cr(NO)L(5-n)Xn](2-n)+,n = 0~1

Wigley, D. E.; Walton, R. A. Organometallics 1982, 1, 1322-1327


Paramagnetic Organochromium Complexeswith 17 Valence Electrons

17 e-

Linear - NO

IR (KBr) νNO 1611 cm-1

IR (hexanes) νNO 1631 cm-1

Peter Legzdins, J. Am. Chem. SOC. 1991, 113, 7049-7050


17 e-

18 e-

18 e-

17 e-

Ligand with Only σ- Donating Character Stabilizes 17 Electron Structure

π-acceptor ligands such as CO stabilize the 18 e- configuration in the neutral complexe.

Linear - NO

IR (Nujol) νNO 1667 cm-1

IR (THF) νNO 1676 cm-1

IR (Nujol) νNO 1709 cm-1

IR (MeCN) νNO 1710 cm-1

IR (Nujol) νCN 2326 cm-1

IR (Nujol) νCN 2297 cm-1

σ-donor ligands such as NH3 & MeCN stabilize the 17 e- cationic compounds.

Peter Legzdins, J.Am. Chem. SOC. 1994, 116, 6021-6022


The First Electron Transfer Chain Catalyzed Ligand Substitution Reaction

Poli, R. J. Am. Chem. Soc. 1992, 114, 1302


M = Cr , Mo , W

18 e- , Singlet S = 0

Paramagnetic Organochromium Complexes

M = Cr

16 e- , Triplet S = 1

M = Mo , W

18 e- , Singlet S = 0

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”

M = Cr

17 e- , Doublet S = 1/2

M = Mo , W

No reaction


M = Cr , Mo , W

18 e- , Singlet S = 0

Synthesis of [OP(2-py)3M(CO)3]

M = Cr ,Mo ,W

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


Crystal structure of [OP(2-py)3M(CO)3]

M = Mo

M = Cr

S. Joyce Yu, J. Organomet. Chem. 1999, 588, 260–267


UV and IR of [OP(2-py)3M(CO)3]

M = Cr,Mo,W

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


M = Cr , Mo , W

M = Cr 16 e- , Triplet S = 1

M = Mo , W 18 e- , Singlet S = 0

Synthesis of [OP(2-py)3M(CO)2(NO)](BF4)

M = Cr ,Mo ,W

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


Crystal structure of [OP(2-py)3M(CO)2(NO)](BF4)

M = Cr

M = W

M = Mo

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


SQUID Data of [OP(2-py)3Cr(CO)2(NO)](BF4)

μeff = g(S(S+1))1/2 ;

S=1,g = 1.9790代入

μeff =2.80(計算值)

μeff = (3k/Nβ2)1/2(χmT)1/2

= 2.828(χmT)1/2

實驗值μeff :2.87

=> Triplet S = 1

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


理論值μeff :2.80

實驗值μeff :2.87

Robert H. Crabtree, The organometallic chemistry of the transition metals, Wiley


UV and IR of [OP(2-py)3M(CO)2(NO)](BF4)M = Cr ,Mo ,W

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


M = Cr , Mo , W

M = Cr 16 e- , Triplet S = 1

M = Mo , W 18 e- , Singlet S = 0

Synthesis of [OP(2-py)3M(CO)(NO)2](BF4)2M = Cr ,Mo ,W

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


Crystal structure of [OP(2-py)3M(CO)(NO)2](BF4)2

M = Cr

M = Mo

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


SQUID Data of [OP(2-py)3Cr(CO)(NO)2](BF4)2

μeff = g(S(S+1))1/2 ;

S=1,g = 1.9560代入

μeff =2.77(計算值)

μeff = (3k/Nβ2)1/2(χmT)1/2

= 2.828(χmT)1/2

實驗值μeff :2.86

=> Triplet S = 1

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


理論值μeff :2.77

實驗值μeff :2.86

Robert H. Crabtree, The organometallic chemistry of the transition metals, Wiley


UV and IR of [OP(2-py)3M(CO)(NO)2](BF4)2M = Cr ,Mo ,W

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


[OP(2-py)3Cr(MeCN)2(NO)](BF4)2

*

[OP(2-py)3Mo(CO)(NO)2](BF4)2

CD3NO2

[OP(2-py)3W(CO)(NO)2](BF4)2

Synthesis of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2

M = Cr

17 e- , Doublet S = 1/2

M = Mo , W

18 e- , Singlet S = 0

M = Cr , Mo , W


IR of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2

1eq NO

νCNνCNνNO

Cr 2323 2295 1753

νCOνCOνNO

Cr 2047 1970 1718

Mo 2036 1953 1685

W 2017 1933 1670

2eq NO

νCNνCNνNO

Cr 2323 2295 1753

νCOνNOνNO

Cr 2029 1889 1742

Mo 2037 1826 1716

W 2148 1774 1687


UV of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2

2eq NO

1eq NO


Crystal structure of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2

Bond angle (o)

C18-N6-Cr1:169.2(3)

C16-N4-Cr1:176.2(3)

O2-N5-Cr1:179.1(3)

Bond length (Å)

Cr1-N5:1.696(3)

Cr1-N4:2.044(3)

Cr1-N6:2.045(3)


Exp.

B3LYP/6-31G(d)

457

400

735

Theoretical studiesof

[OP(2-py)3Cr(MeCN)2(NO)](BF4)2


Theoretical studies of

[OP(2-py)3Cr(MeCN)2(NO)](BF4)2


EPR of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2

gav = 1.9896

Solid

77 K

Wigley, D. E.; Walton, R. A. Organometallics1982, 1, 1322-1327.


SQUID Data of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2

μeff = g(S(S+1))1/2 ;

S=0.5,g = 1.9896代入

μeff =1.72(計算值)

μeff = (3k/Nβ2)1/2(χmT)1/2

= 2.828(χmT)1/2

實驗值μeff :1.90

=> Doublet S = 1/2


理論值μeff :1.72

實驗值μeff :1.90

Robert H. Crabtree, The organometallic chemistry of the transition metals, Wiley


EPR and SQUID data of Cr complexes

[OP(2-py)3Cr(MeCN)2(NO)](BF4)2 1.9896 1.72 / 2.09

林敬糧 碩士論文 2006 “亞硝醯基陽離子與C3v多吡啶磷和

氧化磷鉻羰錯合物的取代反應。有機鉻金屬路易士酸催化活性的探討”


MeCN

CV


CV of [OP(2-py)3Cr(CO)2(NO)](BF4)

Solvent: MeCN

Electrolyte:Tetrabutylammonium

perchlorate

-0.7187 V

-0.4986 V

1.4714 V

2.0250 V


Solvent: MeCN

Electrolyte:Tetrabutylammonium

perchlorate

0.1330 V

0.7085 V

0.2241 V

0.9985 V

CV of [OP(2-py)3Cr(CO)3


Solvent: MeCN

-0.6874 V

Electrolyte:Tetrabutylammonium

perchlorate

1.9430 V

CV of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2


16 e-

18 e-

17 e-

17 e-

17 e-

Peter Legzdins, Organometallics 1995, 14, 4721-4731

Peter Legzdins, J. Am. Chem. SOC. 1994,116, 6021-6022


Conclusions

  • We find a piece of special 17-electronic chromium compound, and characterize with IR, UV, CV, EPR, SQUID and X-ray.

  • We also try to put forward a rational mechanism to explain how to produce the 17-electron compound.


Plausible Formation Pathways for 17-e- complex


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