Issue 42, 2019

Bi- and tridentate stannylphosphines and their coordination to low-valent platinum

Abstract

Semirigid bifunctional tin-substituted o-tolylphosphines of general formulae [Ph2P(o-C6H4CH2)SnR3] (R = Ph, 1; R = Me, 2) and [{Ph2P(o-C6H4CH2)}2SnPh2] (3) were synthesized and isolated in good yields. The new compounds were fully characterized by single-crystal X-ray diffraction and multinuclear solution NMR spectroscopic techniques. The observed J(119Sn,31P) values in solution NMR spectroscopy as well as the P⋯Sn distances in the solid state and DFT calculations (B3LYP) on compounds 1 and 3 do not support the existence of intramolecular P → Sn bond interactions in either of the three compounds. 1 and 2 reacted with stoichiometric amounts of tristriphenylphosphine platinum(0) [Pt(PPh3)3] under toluene refluxing conditions leading to formation of Pt(II) distorted square-planar complexes [Ph2P(o-C6H4CH2)Pt(SnR3)(PPh3)], (R = Ph, 4; R = Me, 5), each bearing a five-membered carbometallated ring resulting from Pt coordination to P and the benzylic C sp3 atom of the ligand architecture rather than from activation of the terminal Sn–C carbon bonds of the phenyl or methyl substituents which would have rendered six-membered rings. Additionally, the fragment SnR3 also binds to the metal centre disposing cis to the cyclometalated carbon atom and to the single remaining PPh3. This carbometallation takes place affecting the integrity of the ligand skeleton. NBO calculations show the Sn fragment coordinates to the metal as X-type stannyl, SnR3. The analogous reaction of [Pt(PPh3)3] towards the stannyldiphosphine 3 leads to the quantitative formation of complex [(Ph2P-o-C6H4CH2)Pt(Ph2P-o-C6H4CH2SnPh3)], 6, which exhibits five- and six-membered metallacycles at the expense of the ligand frame. All compounds were characterized exhaustively by solution spectroscopic measurements and by single crystal X-ray diffraction analysis. DFT computations corroborate the higher stability of the observed products over those resulting from preservation of the ligand backbone.

Graphical abstract: Bi- and tridentate stannylphosphines and their coordination to low-valent platinum

Supplementary files

Article information

Article type
Paper
Submitted
15 ဩ 2019
Accepted
19 စက် 2019
First published
19 စက် 2019

Dalton Trans., 2019,48, 15896-15905

Bi- and tridentate stannylphosphines and their coordination to low-valent platinum

J. J. Salazar-Díaz, M. A. Muñoz-Hernández, E. Rufino-Felipe, M. Flores-Alamo, A. Ramírez-Solís and V. Montiel-Palma, Dalton Trans., 2019, 48, 15896 DOI: 10.1039/C9DT03317C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements