Novel [Rh(η-diene)Tpx] complexes of sterically encumbered Tpx ligands (Tpx = Tp4Bo, diene = cod, 1; nbd, 2; Tpx = Tp4Bo,5Me, diene = cod, 3; nbd, 4; Tpx = Tpa,3Me, diene = cod, 5; nbd, 6; Tpx = Tpa*,3Me, diene = cod, 7; nbd, 8) have been prepared by treatment of [Rh(η-diene)(μ-Cl)]2 with TlTpx (Tpx in general, in detail: Tp4Bo = hydrotris(indazol-1-yl)borate, Tp4Bo,5Me = hydrotris(5-methyl-indazol-1-yl)borate, Tpa,3Me = hydrotris(3-methyl-2H-benz[g]-4,5-dihydroindazol-2-y1)borate, Tpa*,3Me = hydrotris(3-methyl-2H-benz[g]indazol-2-yl)borate), and characterized by analytical and spectral data (IR, 1H, 11B, and 13C NMR solution). The structures adopted by [Rh(nbd)Tp4Bo] 2, [Rh(cod)Tp4Bo,5Me] 3, [Rh(nbd)Tpa,3Me] 6, [Rh(nbd)Tpa*,3Me] 8, and [Rh(nbd)Tpa*,3Me*] 8* (incorporating a borotropomeric ligand), have been investigated. Low steric hindrance between the ligands in 2 and 3 permits κ3 coordination of the pyrazolylborate while the high steric encumbrance present in 6, 8, and 8* results in κ2 ligands. The coordinationmodes of the ligands to the metal have also been established by 15N CPMAS studies of selected ligands and their corresponding Rh complexes. These spectroscopic data are in agreement with the 15N chemical shifts obtained by using quantumchemical methods to assist reliable assignments of the experimental values, affording new insights into the extraction of structural information concerning the hapticity (κ2 or κ3) of the poly(pyrazolyl)borate ligands to the Rh metal.

Solid-State 15N CPMAS NMR and Computational Analysis of Ligand Hapticity in Rhodium(η-diene) Poly(pyrazolyl)borate complexes

GOBETTO, Roberto;NERVI, Carlo;CHIEROTTI, Michele Remo;
2010-01-01

Abstract

Novel [Rh(η-diene)Tpx] complexes of sterically encumbered Tpx ligands (Tpx = Tp4Bo, diene = cod, 1; nbd, 2; Tpx = Tp4Bo,5Me, diene = cod, 3; nbd, 4; Tpx = Tpa,3Me, diene = cod, 5; nbd, 6; Tpx = Tpa*,3Me, diene = cod, 7; nbd, 8) have been prepared by treatment of [Rh(η-diene)(μ-Cl)]2 with TlTpx (Tpx in general, in detail: Tp4Bo = hydrotris(indazol-1-yl)borate, Tp4Bo,5Me = hydrotris(5-methyl-indazol-1-yl)borate, Tpa,3Me = hydrotris(3-methyl-2H-benz[g]-4,5-dihydroindazol-2-y1)borate, Tpa*,3Me = hydrotris(3-methyl-2H-benz[g]indazol-2-yl)borate), and characterized by analytical and spectral data (IR, 1H, 11B, and 13C NMR solution). The structures adopted by [Rh(nbd)Tp4Bo] 2, [Rh(cod)Tp4Bo,5Me] 3, [Rh(nbd)Tpa,3Me] 6, [Rh(nbd)Tpa*,3Me] 8, and [Rh(nbd)Tpa*,3Me*] 8* (incorporating a borotropomeric ligand), have been investigated. Low steric hindrance between the ligands in 2 and 3 permits κ3 coordination of the pyrazolylborate while the high steric encumbrance present in 6, 8, and 8* results in κ2 ligands. The coordinationmodes of the ligands to the metal have also been established by 15N CPMAS studies of selected ligands and their corresponding Rh complexes. These spectroscopic data are in agreement with the 15N chemical shifts obtained by using quantumchemical methods to assist reliable assignments of the experimental values, affording new insights into the extraction of structural information concerning the hapticity (κ2 or κ3) of the poly(pyrazolyl)borate ligands to the Rh metal.
49
11205
11215
Riccardo Pettinari; Claudio Pettinari; Fabio Marchetti; Roberto Gobetto; Carlo Nervi; Michele R. Chierotti; Eric J. Chan; Brian W. Skelton; Allan H. White
File in questo prodotto:
File Dimensione Formato  
067_ic101830e.pdf

Accesso riservato

Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 1.25 MB
Formato Adobe PDF
1.25 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/79324
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 20
  • ???jsp.display-item.citation.isi??? 19
social impact