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

SpeakerPo-Yuan ChungSupervisor : Prof. Shuchun Joyce YuDate2008/06/16

OutlineIntroduction - 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 ElectronsStrametz, H.; Fischer, E. O. J. Organomet. Chem. 1967, 10, 32318 e-17 e-

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 SpeciesCpCrL3MICHAEL 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 = 0~1Wigley, D. E.; Walton, R. A. Organometallics 1982, 1, 1322-1327

Paramagnetic Organochromium Complexeswith 17 Valence ElectronsPeter Legzdins, J. Am. Chem. SOC. 1991, 113, 7049-705017 e-Linear - NOIR (KBr) NO 1611 cm-1IR (hexanes) NO 1631 cm-1

Ligand with Only - Donating Character Stabilizes 17 Electron StructurePeter Legzdins, J. Am. Chem. SOC. 1994, 116, 6021-6022-donor ligands such as NH3 & MeCN stabilize the 17 e- cationic compounds.-acceptor ligands such as CO stabilize the 18 e- configuration in the neutral complexe.Linear - NOIR (Nujol) NO 1667 cm-1IR (THF) NO 1676 cm-1IR (Nujol) NO 1709 cm-1IR (MeCN) NO 1710 cm-1IR (Nujol) CN 2326 cm-1IR (Nujol) CN 2297 cm-1

The First Electron Transfer Chain Catalyzed Ligand Substitution ReactionPoli, R. J. Am. Chem. Soc. 1992, 114, 1302

Paramagnetic Organochromium Complexes 2006 C3v16 e- , Triplet S = 117 e- , Doublet S = 1/2M = CrM = Mo , W18 e- , Singlet S = 0M = CrM = Mo , WNo reaction

Synthesis of [OP(2-py)3M(CO)3]M = Cr Mo W 2006 C3v

Crystal structure of [OP(2-py)3M(CO)3]M = CrM = MoS. Joyce Yu, J. Organomet. Chem. 1999, 588, 260267

UV and IR of [OP(2-py)3M(CO)3]M = CrMoW 2006 C3v

Synthesis of [OP(2-py)3M(CO)2(NO)](BF4)M = Cr Mo W 2006 C3v

Crystal structure of [OP(2-py)3M(CO)2(NO)](BF4)M = CrM = W 2006 C3vM = Mo

SQUID Data of [OP(2-py)3Cr(CO)2(NO)](BF4)eff = g(S(S+1))1/2 ;

S=1g = 1.9790

eff =2.80 ()

eff = (3k/N2)1/2(mT)1/2

= 2.828(mT)1/2

eff :2.87 2006 C3v=> Triplet S = 1

Robert H. Crabtree, The organometallic chemistry of the transition metals, Wiley eff :2.80

eff :2.87

UV and IR of [OP(2-py)3M(CO)2(NO)](BF4) M = Cr Mo W 2006 C3v

Synthesis of [OP(2-py)3M(CO)(NO)2](BF4)2M = Cr Mo W 2006 C3v

Crystal structure of [OP(2-py)3M(CO)(NO)2](BF4)2M = MoM = Cr 2006 C3v

SQUID Data of [OP(2-py)3Cr(CO)(NO)2](BF4)2eff = g(S(S+1))1/2 ;

S=1g = 1.9560

eff =2.77 ()

eff = (3k/N2)1/2(mT)1/2

= 2.828(mT)1/2

eff :2.86 2006 C3v=> Triplet S = 1

Robert H. Crabtree, The organometallic chemistry of the transition metals, Wiley eff :2.77

eff :2.86

UV and IR of [OP(2-py)3M(CO)(NO)2](BF4)2 M = Cr Mo W 2006 C3v

Synthesis of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2M = Cr17 e- , Doublet S = 1/2M = Mo , W18 e- , Singlet S = 0M = Cr , Mo , W

IR of [OP(2-py)3Cr(MeCN)2(NO)](BF4)21eq NO CN CN NO Cr 2323 2295 1753 CO CO NO Cr 2047 1970 1718Mo 2036 1953 1685W 2017 1933 1670 2eq NO CN CN NO Cr 2323 2295 1753 CO NO NO Cr 2029 1889 1742Mo 2037 1826 1716W 2148 1774 1687

UV of [OP(2-py)3Cr(MeCN)2(NO)](BF4)21eq NO2eq NO

Crystal structure of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2Bond length ()Cr1-N51.696(3)Cr1-N42.044(3)Cr1-N62.045(3)Bond angle (o)C18-N6-Cr1169.2(3) C16-N4-Cr1176.2(3)O2-N5-Cr1179.1(3)

Theoretical studies of [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)2gav = 1.9896Wigley, D. E.; Walton, R. A. Organometallics 1982, 1, 1322-1327.Solid77 K

SQUID Data of [OP(2-py)3Cr(MeCN)2(NO)](BF4)2 eff = g(S(S+1))1/2 ;

S=0.5g = 1.9896

eff =1.72 ()

eff = (3k/N2)1/2(mT)1/2

= 2.828(mT)1/2 eff :1.90=> Doublet S = 1/2

Robert H. Crabtree, The organometallic chemistry of the transition metals, Wiley eff :1.72

eff :1.90

EPR and SQUID data of Cr complexes 2006 C3v[OP(2-py)3Cr(MeCN)2(NO)](BF4)2 1.9896 1.72 / 2.09

CV

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

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

Peter Legzdins, Organometallics 1995, 14, 4721-4731Peter Legzdins, J. Am. Chem. SOC. 1994,116, 6021-602217 e-

ConclusionsWe 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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