Large, weakly basic bis(carboranyl)phosphines: an experimental and computational studyDedicated to Professor Evamarie Hey-Hawkins on the occasion of her 60th birthday.Electronic supplementary information (ESI) available: NMR spectra of all new compounds reported. Full details of computational studies. CCDC 1527028-1527033. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7dt00485k
The bis(carboranyl)phosphines [μ-2,2′-PPh-{1-(1′-1′,2′- closo -C 2 B 10 H 10 )-1,2- closo -C 2 B 10 H 10 }] ( I ) and [μ-2,2′-PEt-{1-(1′-1′,2′- closo -C 2 B 10 H 10 )-1,2- closo -C 2 B 10 H 10 }] ( 1 ) have been prepared and spectroscopically and structurally characterised. Crystallographic and DFT...
Saved in:
| Main Authors | , , , , , , |
|---|---|
| Format | Journal Article |
| Language | English |
| Published |
19.04.2017
|
| Online Access | Get full text |
Cover
Loading…
| Summary: | The bis(carboranyl)phosphines [μ-2,2′-PPh-{1-(1′-1′,2′-
closo
-C
2
B
10
H
10
)-1,2-
closo
-C
2
B
10
H
10
}] (
I
) and [μ-2,2′-PEt-{1-(1′-1′,2′-
closo
-C
2
B
10
H
10
)-1,2-
closo
-C
2
B
10
H
10
}] (
1
) have been prepared and spectroscopically and structurally characterised. Crystallographic and DFT computational studies of
1
suggest that the orientation of the ethyl group, relative to the bis(carborane), is the result of intramolecular dihydrogen bonding. This orientation is such that the magnitudes of the
2
J
PH
coupling constants are approximately equal but of opposite sign, and fast exchange between the methylene protons in solution leads to an observed
2
J
PH
close to zero. The steric properties of
I
,
1
and their derivatives [μ-2,2′-P(Ph)AuCl-{1-(1′-1′,2′-
closo
-C
2
B
10
H
10
)-1,2-
closo
-C
2
B
10
H
10
}] (
2
) and [μ-2,2′-P(Et)AuCl-{1-(1′-1′,2′-
closo
-C
2
B
10
H
10
)-1,2-
closo
-C
2
B
10
H
10
}] (
3
) have been assessed by Tolman cone angle and percent buried volume calculations, from which it is concluded that the bis(carboranyl)phosphines
I
and
1
are comparable to PCy
3
in their steric demands. The selenides [μ-2,2′-P(Ph)Se-{1-(1′-1′,2′-
closo
-C
2
B
10
H
10
)-1,2-
closo
-C
2
B
10
H
10
}] (
4
) and [μ-2,2′-P(Et)Se-{1-(1′-1′,2′-
closo
-C
2
B
10
H
10
)-1,2-
closo
-C
2
B
10
H
10
}] (
5
) have also been prepared and characterised. The
1
J
PSe
coupling constants for
4
and
5
are the largest reported so far for carboranylphosphine selenides and indicate that
I
and
1
are very weakly basic.
Bis(carboranyl)phosphines and their {AuCl} and {Se} derivatives have been the subject of experimental and computational studies. |
|---|---|
| Bibliography: | For ESI and crystallographic data in CIF or other electronic format see DOI th 10.1039/c7dt00485k 1527028-1527033 Electronic supplementary information (ESI) available: NMR spectra of all new compounds reported. Full details of computational studies. CCDC Dedicated to Professor Evamarie Hey-Hawkins on the occasion of her 60 birthday. |
| ISSN: | 1477-9226 1477-9234 |
| DOI: | 10.1039/c7dt00485k |