Stannylenes as Ligands in Transition Metal Complexes


Study Targets

Synthetic access to transition metal complexes with main group ligands

Influence of complexation on structural, spectroscopic fluxional and reactivity behaviour of unsaturated low valent group-14 molecules (stannylenes)

 

Coordination of

Main Group Fragments: Stannylenes

Stannylene Complexes

  1. AufzählungszeichenMolecular Structures

  2. AufzählungszeichenNMR Spectroscopy

  3. Heteronuclear

  4. Solid State

  5. Dynamics

M. Veith, M. Ehses, V. Huch, New J. Chem. 2005, 29, 154-64.

A Rational to Degradation of the P4 Tetrahedron

The most part of structures derived of transition metal complexes with „naked“ phosphorus ligands Pn (n≤4) can be rationalised by stepwise opening of edges in the P4 tetrahedron. For each of the above structural motives, ligands incorporated in transition metal complexes are described.

The formal opening of an edge can also be regarded as step-wise reduction of P4 with electron pairs forming (poly-)phosphide anions. Some of these are characterised as Zintl ions.


Study Targets

Understanding Transition Metal-Main Group element interaction. To this aim, the complexes from the interaction of (unsaturated) transition metal complexes are synthesised and characterised.

This concept is currently extended to the interaction of unsaturated main group compounds with elemental phosphorus.


Molecular Structures

Transition Mediated

Activation of White Phosphorus

Papers

  1. AufzählungszeichenM. Ehses, A. Romerosa, M. Peruzzini Top. Curr. Chem. 2002, 220(New Aspects in Phosphorus Chemistry I), 107-40.

  2. AufzählungszeichenM. Di Vaira, M. P. Ehses, M. Peruzzini, P. Stoppioni J. Organomet. Chem. 2000, 593/594, 127-34.

  3. AufzählungszeichenM. Di Vaira, M. P. Ehses, P. Stoppioni, M. Peruzzini Inorg. Chem. 2000, 39, 2199-205.

  4. AufzählungszeichenM. Di Vaira, M. P. Ehses, M. Peruzzini, P. Stoppioni Eur. J. Inorg. Chem. 2000, 10, 2193-8.

  5. AufzählungszeichenO. Scherer, C. Hofmann, M. Ehses, S. Weigel, G. Wolmershäuser Phosphorus Sulfur Silicon Rel. Elem. 1999, 146, 141-4.

  6. AufzählungszeichenM. Di Vaira, M. P. Ehses, M. Peruzzini, P. Stoppioni Polyhedron 1999, 18, 2331-6.

  7. AufzählungszeichenO. J. Scherer, M. Ehses, G. Wolmershäuser Angew. Chem. 1998, 110, 530-3; Angew. Chem., Int. Ed., 1998, 37, 507-10.

  8. AufzählungszeichenO. J. Scherer, M. Ehses, G. Wolmershaeuser J. Organomet. Chem. 1997, 531, 217-21.

Review

The coordination effect of transition metal on stannylenes has been examined analysing 119Sn NMR data and X-ray molecular structures from the literature up to 2008. Coordination deshielding of linearly correlate with the shift of the free stannylene. Slope, intercept and typical regions are interpreted through different ratios of s/p-back bonding and impact of transition metal. substituent and base(s). Hybridisation changes explain dependencies of 1JSn-TM coupling constants on ligands on the transition metal, substituents, bases and transition metal gyromagnetic ratios. The Sn-TM bond lengths follow a parabolic profile along the TM period, fine-tuned by substituent, ligand and bases. Electronic modifications on carbonyl complexes classify stannylenes as poor π(pi)-acceptors, while shortening of the tin-substituent bond and widening of the angle correspond to increased s-character of the Sn-transition metal bond. A ‘‘coordinative Lewis base radius’’ r(SnR) of 1.18Å is proposed. See article: „119Sn NMR spectroscopic and structural properties of transition metal complexes with terminal stannylene ligands“: D. Agustin, M. Ehses, Comptes Rendus Chimie, 2009 (in print for October 2009, doi: 10.1016/j.crci.2009.04.004).

coordination chemical shift against chemical shift of stannylenenes

Sn-Transition metal bond lengths in stannylene complexes