Matthias Zeller

Properties and Reactivity of Triphospholyl-Metal-Complexes

YSU Jan 17th 2003

R [M] [M] YSU Jan 17th 2003 What are Triphospholyl Complexes?

[M] Influence on: • structure • electronic properties • reactivity etc P [M] t Bu P P [M] P t Bu

YSU Jan 17th 2003

What can be modified?

• Structure and Bonding Types Influence of free electron pair • Electronic Properties Degeneration of Frontier Orbitals, Sequence of Orbitals, Redox Potentials • Reactivity: Known Reactions  Reaction Rate and Products Novel Reactions  Stability and Decomposition Reactions

YSU Jan 17th 2003 What was known before: MX 2 + 2 t Bu P P P t Bu [Li(DME) 3 ] 2 LiX t Bu t Bu P P P M P P t Bu P t Bu M = Fe (30 %) Ru (15 %) Cr (< 1 %) [NiBr 2 (DME) 2 ] + t t Bu Bu P P P t Bu [Li(DME) 3 ] P P t Bu [Li(DME) 3 ] t Bu 2 LiBr ~ 5% t Bu t Bu P P Ni P P P t Bu t Bu t Bu J. F. Nixon et al., J. Chem. Soc., Chem. Commun. 1987 ,

373

, 1146-1148; J. Organometal. Chem.1988 ,

365

, C1-C4;

J. Organometal. Chem

.

1995

,

490

, 155-162; J. Organometal. Chem. 1989 ,

373

, C17-C20.

YSU Jan 17th 2003 Our Starting Materials: t Bu P P P t Bu [Na(THF) x ] R 3 SnCl toluene, 30°C > 80% t Bu P t Bu P P SnR 3 + NaCl R = Me, Ph,

n

-Bu A. Elvers, F. Heinemann, B. Wrackmeyer, U. Zenneck,

Chem. Eur. J

.

1999

,

5

, 3143-3153.

YSU Jan 17th 2003 Some first new Compounds: t Bu P t Bu P P SnPh 3 SnCl 2 + 2 t Bu P t Bu P P SnMe 3 Mn(CO) 5 Br THF, 61% THF 98% t Bu P P P Mn (CO) 3 t Bu + BrSnPh 3 t Bu t Bu P P P Sn P P P t Bu t Bu + 2 ClSnMe 3 t Bu P t Bu P P SnPh 3 CpCo(C 2 H 4 ) 2 82 % t Bu P Co SnPh 3 P P t Bu filtration through Florisil ® t Bu - "SnPh 3 " P P Co A.Elvers, T. Clark, F. W. Heinemann, M. Hennemann, M. Zeller, U. Zenneck, Angew. Chem. 2000 ,

112

, 2174-2178; A. Elvers, F. W. Heinemann, B. Wrackmeyer, U. Zenneck,

Chem. Eur. J

.

1999

,

5

, 3143-3153.

P t Bu

YSU Jan 17th 2003 Paramagnetic 16 and 17 VE Complexes: MX 2 + 2 t Bu P t Bu P P SnMe 3 - 2 XSnMe 3 t Bu t Bu P P P M P P t Bu P t Bu M = Mn: 28 % Cr: 57 % MX 2 = Mn{N(SiMe 3 ) 2 } 2 , CrCl 2 (THF) 2 Compare to R. Bartsch, P. B. Hitchcock, J. F. Nixon, J. Organometal. Chem. 1988 ,

356

, C1-C4.

YSU Jan 17th 2003 t Bu t Bu P P P Mn P P t Bu P t Bu EPR Spectra in

n

-Hexane: rt = 2.007

= 78.9 G 120 K, glassy frozen solution g  = 1.996, A  ~ 0 G g  = 2.029, A  = 115.7 G

d yz , d xz d xy , d x2-y2 d z2 Phosphorous in the Cp Ring  Change of Orbital Sequence 6 A 1 2 E 2 2 A Substitution CR P d yz , d xz d z2 d xy , d x2-y2 YSU Jan 17th 2003 e.g. Mn(Cp) 2 e.g. Mn(Cp*) 2 Mn Mn Mn(P 3 C 2 -

t

-Bu 2 ) 2 t Bu t Bu P P P Mn P P t Bu P t Bu

YSU Jan 17th 2003 Redox Potential Shifts t Bu t Bu P P P Cr P P P t Bu t Bu + + 0.86 V t t Bu Bu P P P Cr P P t Bu P t Bu 0.51 V t t Bu Bu P P P Cr P P P t Bu t Bu stable, isolable!

vs Cp 2 Cr the shifts are 1.7 to 2.0 V !

YSU Jan 17th 2003 Reduction of ´(P 3 C 2 ) 2 Cr´ with K/Na: EPR Spectrum in Toluene: exp.

sim.

YSU Jan 17th 2003 Triphospholyl Halfsandwich Complexes: t Bu P t Bu P P SnPh 3 Co 2 (CO) 8

n

-hexane, ~20% t Bu P P P O C Co C O t Bu Smp.: ~ 10°C

YSU Jan 17th 2003 PR 3 h  , 10 - 15 min Carbonyl Substitution under mild Conditions: t Bu P P P O C Co C O t Bu 2 eq.

C N 60°C  rt Cy t Bu P P O C Co P PR 3 t Bu R = Et: 51 % R = Ph: 69 % t Bu P t Bu P P Cy N C Co C N Cy 76 % + t Bu P P P Cy N C Co C O t Bu 9 %

YSU Jan 17th 2003 Carbonyl Substitution under mild Conditions: t Bu P P P O C Co C O t Bu PR 3 h  , 10 - 15 min,

n

-hexane t Bu P P O C Co P PR 3 t Bu R = Et: 51 % R = Ph: 69 % Analogous Carbon Complex: 24 h Reflux in Hexane needed

YSU Jan 17th 2003 t Bu P P P O C Co C O t Bu 2 eq.

C N Cy

n

-hexane -60°C  rt t Bu P t Bu P P Cy N C Co C N Cy 76 % + t Bu P P P Cy N C Co C O t Bu 9 % Analogous Carbon Complex: Only Monosubstitution with CN-Cy

YSU Jan 17th 2003 t Bu O P P P t Bu C Mn PMe 3 PMe 3 Carbonyl Substitution with P 3 -Cymantrene: PMe 3 , h  , 15 min 74 % t Bu P P P O C Mn C C O O t Bu CN-Cy, 70°C, 3h 52 % t Bu P t Bu P P O C Mn C C O N Cy

n

-hexane, h  , 15 min t Bu P O t Bu C P P Mn C O

rac

O P P C C Mn O t Bu P t Bu + ~ 20 % t Bu O P t Bu C P Mn P O P P C C Mn O t Bu P C O

meso

t Bu ~ 40%

t Bu P P P O C Mn C C O O t Bu

n

-hexane, h  , 15 min YSU Jan 17th 2003 t Bu P O t Bu C P P Mn C O

rac

O P P C C Mn O t Bu P t Bu ~ 20 % + t Bu O P t Bu C P Mn P O P Mn P C C O t Bu P C O

meso

t Bu ~ 40%

31 P NMR Spectrum: YSU Jan 17th 2003

t Bu P P P O C Mn C O C O t Bu PMe 3 , h  , 15 min 74 % t Bu P P P t Bu O C Mn PMe 3 PMe 3 Analogous Carbon Complex: > 90 Minutes Irradiation needed for Disubstitution!

t Bu P P P O C Mn C O C O t Bu CN-Cy, 70°C, 3h Analogous Carbon Complex: No Reaction! t Bu P t Bu P P O C Mn C O C N Cy YSU Jan 17th 2003

31 P-NMR-Spectra at variable Temperatures: hindered Rotation of the Triphospholyl Ring ( D H  = 53 kJmol –1 ) YSU Jan 17th 2003

YSU Jan 17th 2003 Enhanced Reaction Rates: Why?

Cymantrene: Dissociative Mechanism!

h  O C Mn C C O O 18 VE O C Mn C O 16 VE L Triphospha Cymantrene: Associative Mechanism?

t Bu t Bu P O C Mn C P P C O O L L O t Bu P P t Bu C C Mn C P L O O 18 VE 18 VE O C Mn C O 18 VE L CO t Bu t Bu P O C Mn C P P O L 18 VE

YSU Jan 17th 2003 Triphospholyl Nickel Complexes NiCl 2 (PPh 3 ) 2 + t Bu P t Bu P P SnMe 3 CH 2 Cl 2 40°C  rt t Bu P P P Cl Ni 74 % PPh 3 t Bu + PPh 3 + ClSnMe 3 Compare.: Cl M PPh 3 M = Ni, Pd, Pt But: t Bu P t Bu P P PR 3 M Cl R 3 P M = Pd, Pt See also: R. Bartsch, D.Carmichael, P. B. Hitchcock, M. F. Meidine, J. F. Nixon, G. J. D. Sillet,

J. Chem. Soc., Chem. Commun.

1988

, 1615-1617.

YSU Jan 17th 2003 t [ClNi(NO){P(C 6 H 5 ) 3 } 2 ] Bu + P t Bu P P SnMe 3 A Nickel Nitrosyl Complex: CH 2 Cl 2 ClSnMe 3 P(C 6 H 5 ) 3 t Bu P t Bu (C 6 H 5 ) 3 P ON Ni P P t Bu P P P Ni NO P(C 6 H 5 ) 3 t Bu 70 % With Cyclopentadienyl: Ni N O

A Reversible and Temperature Dependant   -Rearrangement: YSU Jan 17th 2003 2 t Bu P P P Ni N O red t Bu + 2 P(C 6 H 5 ) 3 90°C rt t Bu P t Bu (C 6 H 5 ) 3 P ON Ni P P t Bu P P P Ni NO P(C 6 H 5 ) 3 t Bu black-green 31 P NMR Spectra:

2 t Bu P Ni N O red P P YSU Jan 17th 2003 Trapping of the Piano Stool Complex t Bu t Bu + 2 P(C 6 H 5 ) 3 90°C rt P t Bu (C 6 H 5 ) 3 P ON P Ni P t Bu P P P Ni NO P(C 6 H 5 ) 3 t Bu black-green (CO) 5 (THF)W Ph 3 PW(CO) 5 t Bu (OC) 5 W P P Ni P N O t Bu red, 20 %

What about Copper(I) Piano Stool Complexes?

0.25 [ClCu{P(C 6 H 5 ) 3 }] 4 t Bu + P t Bu P P SnMe 3 ClSnMe 3 t Bu P P P Cu P t Bu +48°C +25°C -30°C -70°C -90°C 83 % YSU Jan 17th 2003

YSU Jan 17th 2003 An Equilibrium of three Isomers?

t Bu P P P Cu P t Bu t Bu D G  = 44 - 50 kJ/mol D H = 1.8 kJ/mol D S = +7.1 J/Kmol P P t Bu P Cu P(C 6 H 5 ) 3 D G D G  = 31 kJ/mol  = 37 kJ/mol t Bu P t Bu P P Cu P(C 6 H 5 ) 3 D G   37 kJ/mol t Bu P Cu (H 5 C 6 ) 3 P P P t Bu D G  = 37 kJ/mol t Bu P (H 5 C 6 ) 3 P Cu P P t Bu

t Bu P P P Cu P t Bu (THF)(CO) 5 W Trapping with (OC) n W: (OC) 5 W t Bu P P Cu P t Bu P + (OC) 5 W t Bu P P P t Bu P Cu O W C C C O O 33 % 7 %

t Bu P P (OC) 5 W Cu P t Bu P D G  = 55.6 kJ/mol (OC) 5 W t Bu P P Cu P t Bu P YSU Jan 17th 2003 (OC) 5 W t Bu P P P t Bu P Cu O W C C C O O D G  = 44.4 kJ/mol t Bu P P P W(CO) 5 t Bu P Cu O W C C C O O

31 P NMR Spectra at variable Temperatures: YSU Jan 17th 2003

(OC) 5 W YSU Jan 17th 2003 t Bu P P Cu P t Bu P 1,2-Shift or 1,5-sigmatropic Rearrangement  1 (  )  1 (  ) t Bu (OC) 5 W P P Cu P t Bu P divergent orbitals (OC) 5 W P P P t Bu t Bu Cu P  1 (  )  1 (  ) parallel orbitals (OC) 5 W P P P t Bu t Bu Cu P

31 P NMR Spectra at variable Temperatures: YSU Jan 17th 2003

YSU Jan 17th 2003 31 P NMR Coupling Constants: 47.6

(OC) 5 W 373.0

t Bu b P P c d 56.9

P P a t Bu Cu O C W C C 39.5

O O t Bu 39.0

50.1

P d 391.2

P c P a Cu O C W C C O P b 40.8

t Bu W(CO) 5 O

YSU Jan 17th 2003 Is a Hexaphospha Mercurocene possible

?

2 t Bu P P P SnMe 3 t Bu + HgCl 2 2 Me 3 SnCl t Bu P P t Bu P P Hg P t Bu P t Bu 95 % t Bu P Hg P t Bu P t Bu P P P t Bu unsoluble solid, CP-MAS 31 P NMR Spectra:

two

signals

t Bu YSU Jan 17th 2003 P P t Bu P P Hg P t Bu P t Bu A Radical Elimination Reaction ?

unpolar solvent 72 % t Bu P t Bu P t Bu P P P P t Bu + Hg Vergl.: A. Mack, M. Regitz, Advances in Strained and Interesting Molecules, Suppl. 1 1999 , 199.

YSU Jan 17th 2003 Under Irradition further Rearrangement occurs: t Bu P t Bu P t Bu P P P P t Bu h  (daylight), 2h 40 % t Bu P t Bu P P P P t Bu P t Bu Vergl.: A. Mack, M. Regitz, Advances in Strained and Interesting Molecules, Suppl. 1 1999 , 199.

31 P NMR Spectrum: YSU Jan 17th 2003

YSU Jan 17th 2003 31 P NMR Spectrum: Exp.: Sim.: A X Y Y` 31 3.56

29.55

–6.74

P NMR Coupling Constants Y 33.33

–3.80

X` 4.46

5.99

X A` –86.42 63.74

t Bu A P X P t Bu P A` P X` P Y t Bu P Y` t Bu

Summary: The Inclusion of

Phosphorous Atoms in coordinated



-Ligands

influences the properties of the complexes remarkably They show, when compared to Complexes with pure carbacyclic Ligands  Change of

electronic

properties (hexaphospha metallocenes),  novel

structural

properties (Ni and Cu complexes),  modified

reactivity

(CO substitution reactions),  novel

decompostion

reactions (hexaphospha mercurocene) YSU Jan 17th 2003

YSU Jan 17th 2003 Acknowledgements and Appreciations:

Prof. Ulrich Zenneck, the Zenneck Group

Dr. F. W. Heinemann (X-Ray), Dr. H. Pritzkow (X-Ray, Heidelberg), Dr. M. Moll (low temp NMR), PD Dr. W. Bauer (CP-MAS Spectra), Dr. O. Waldmann (SQUID-Measurements), Dr. G. Brehm und G. Sauer (Raman-Spectra), J. Kurzawa (UV-Vis-Spectra) Graduiertenkolleg ´Phosphorchemie als Bindeglied verschiedener Disziplinen´ ´StuSti´ (Studienstiftung des deutschen Volkes)