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Welcome to the Mountford Group web pages. We
are working on the synthesis and stoichiometric and catalytic chemistry of
organometallic compounds of a range of transition, lanthanide and main
group metals, from both a fundamental and applied point of view. We
are particularly interested in the following areas (click on one of the
links for further details).
The synthesis, bonding and small molecule activation reactions of
transition metal hydrazide complexes
New catalysts for the synthesis of
biodegradable and biocompatible polymers: substitutes for
oil-derived materials
Fundamental and
applied studies of new olefin polymerisation and oligomerisation catalysts
If
you are interested in joining the group then please click
here. If you have any
questions about our research then please
email Philip Mountford.
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Latest news
and publications
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A comprehensive combined
experimental and computational study of the silylation,
alkylation and protonation reactions of
Ti=NNR2 bonds
Dalton Trans., 2012, 41,
2277-2288.
[link to journal]
The first combined study of this type for any
transition metal hydrazide complex (known intermediates in the
general conversion of atmospheric N2
to NH3) is reported.
New Dalton
Transactions editorial board chairman
Philip Mountford has been appointed by the RSC
as Chairman of the Editorial Board of Dalton Transactions for
2012-2015. Dalton is one of the leading international journals in the areas of inorganic, organometallic and bioinorganic
chemistry. For further details
click here.
The first Group 4 metal
bis(imido) and tris(imido) complexes
Chemical Science, 2012,
3, 819-824.
[link to journal]
The synthesis and molecular and electronic
structures of the first Group 4 compounds simultaneously containing two or
three metal-ligand multiple bonds are reported
in the RSC's premier flagship journal.
The first titanium
alkoxyimido complexes
Inorg. Chem., 2011,
50, 12155-12171.
[link to journal]
The synthesis and molecular and electronic
structures of the first alkoxyimido complexes of titanium (Ti=N-OR
functional group)
are reported for a wide range of supporting
ligands.
New group members
We are delighted to welcome new group members
Bryony Core, Lee Collins, Richard Collins and Onn Chee (left to right in
the photograph).
The first
calcium-transition metal bond and a comparison with a
lanthanide-transition metal counterpart
J. Am. Chem. Soc., 2011,
113,
15359-15361.
[link to journal]
The first compound with a Ca-Fe bond is
reported along with an analysis of the unusual bonding in this complex.
Summer visitor
We are delighted to welcome Professor Georgii
Nikonov back to the group for his sabbatical visit this summer. Georgii
and Philip have collaborated on and off for over 15 years so it is a
special pleasure to have him visit again. To see some of Professor
Nikonov's recent work
click here.
Conference news
Congratulations to Richard Scott
(pictured) on being awarded a Poster Prize at the 2011 RSC Coordination
Chemistry meeting. Richard presented some of his recent results on the
chemistry of new olefin polymerisation catalysts complexes, carried out in
collaboration with LANXESS Elastomers B.V. Pei Jen Tiong gave a
lecture at the same meeting entited New terminal titanium hydrazido
complexes: a study of the synthesis and reactivity of the Ti=N-NR2
functional group.
Meanwhile Dr Andrey Protchenko gave a lecture
at the 2011 RSC Main Group Chemistry Meeting entitled Main group metal
and lanthanide complexes derived from the nucleophilic diaminoboryl anion.
Dr Andrew Schwarz and Liban Saleh presented posters at the
EuCOMC XIX organometallics conference in Toulouse on new alkoxyimido and
lanthanide boryl complexes, respectively.
New sandwich and
half-sandwich titanium hydrazido compounds
Organometallics, 2011, 30,
2295–2307.
[link to journal]
The first titanocene hydrazide derivative is
reported along with an analysis of the unusual bonding in this complex.
The first Group 4
alkoxyimido (M=N–OR) complexes: reductive N–O bond cleavage at the
boundary between hydrazide and peroxide ligands
Chem. Commun., 2011, 47,
4926–4928.
[link to journal]
The first Group 4 alkoxyimido compounds are
reported. The Ti=N–OtBu group in Ti(N2NMe)(NOtBu)(py)
undergoes facile 2-electron N–O bond cleavage with PhCCMe as the reductant
to form a 1,2-diamidoalkene group via two highly selective N–C bond
forming events.
The
first Group 3 and lanthanide boryl compounds
J. Am. Chem. Soc. 2011,
133, 3836-3839.
[link to journal]
Reaction of [Ln(CH2SiMe3)2(THF)n][BPh4]
(Ln = Sc, Y or Lu ; n = 3 or 4) with Li{B(NArCH)2}(THF)2
(Ar = 2,6-C6H3iPr2) formed the
first group 3 and lanthanide boryl compounds containing 2-center,
2-electron Ln–B sigma-bonds.
New group member
We are delighted to welcome Dr Yong Huang from
Lanzhou University, PR China. Dr Huang is a Lecturer in the Research
Institute of Coordination Chemistry and Functional Materials. He holds a
China Scholarship Council scholarship that will allow him to pursue his
interests in ring-opening polymerisation catalysis using Group 3 and
lanthanide compounds. To see some of Dr Huang's recent work
click here.
Sulfonamide, phenolate and directing ligand-free indium initiators for the
ring-opening polymerization of rac-lactide
Organometallics, 2011, 30,
1202–1214.
[link to journal]
The synthesis, structures and rac-lactide
ring-opening polymerization (ROP) capability of a series of new indium
initiators based on bis(sulfonamide)amine or bis(phenolate)amine ligands
are reported, along with the amine-coinitiated immortal ROP of rac-lactide
using In(CH2SiMe3)3 or InCl3/Et3N.
Reactions of cyclopentadienyl-amidinate titanium hydrazides with CO2,
CS2 and isocyanates: Ti=N cycloaddition,
cycloaddition-insertion and cycloaddition-NNR2 group transfer
reactions
Organometallics, 2011, 30,
1182–1201.
[link to journal]
Detailed experimental and DFT studies of a
range of transformations of the Ti=NNR2 functional group with
CO2, CS2, isocyanates and isothiocyanates are
reported. These lead to Ti=N cycloaddition, net Ti=N insertion, or NNR2
transfer reactions.
Si-H
and Si-Cl bond activation of titanium hydrazides with silanes and
subsequent Ti-H / E-H (E = Si or H) sigma bond metathesis
Chem. Commun., 2011, 47, 3147-3149.
[link to journal]
The Ti=NNMe2 group of Cp*Ti{MeC(NiPr)2}(NNMe2)
undergoes reversible, concerted 1,2-addition reactions with Si–H bonds and
irreversible addition with Si–Cl bonds; slow sigma bond metathesis between
the first-formed Ti–H bond and Si–H or H–H is also observed.
Cationic and charge-neutral
calcium tetrahydroborate complexes and their use in the controlled
ring-opening polymerisation of rac-lactide
Chem. Commun., 2011, 47, 2276-2278.
[link to journal]
The facile synthesis of the first cationic
main group tetrahydroborates is reported, along with the X-ray structures
of [Ca(BH4)(THF)5][BPh4] and [(Tpm)Ca(BH4)(THF)2][BPh4].
These are initiators for the ring opening polymerization of rac-lactide,
the latter producing PLA in a living manner with high levels of
heterotactic enrichment.
Reaction site diversity in the reactions of
titanium hydrazides with organic nitriles, isonitriles and isocyanates:
Ti=N cycloaddition, Ti=N insertion and N-N bond cleavage
Chem. Eur J., 2011, 17, 265-285. Designated a
"VIP"
paper
by the Editor.
[link to journal]
A combined experimental and DFT study of the
Ti=N and N-N cycloaddition and/or insertion reactions of diamide-amine
supported titanium hydrazides with a range of small unsaturated molecules
is presented.
Conference news
Philip Mountford and DPhil student Lawrence
Clark (pictured) recently presented some of the group's work in lanthanide and main
group catalysed ring-opening polymerisation catalysis at the 23rd Conference on Rare Earth Chemistry in Bayreuth, Germany.
Click here to see
Lawrence's poster and here
for an abstract of Philip's lecture entitled "Cationic and zwitterionic
rare earth and alkaline earth initiators for the living and immortal
ring-opening polymerisation of rac-lactide".
Contrasting reactivity of anionic boron-
and gallium-containing NHC analogues
Chem.
Commun., 2010, 46, 8546-8548. Designated a
"hot article"
by the Editor and allocated the Inside Cover [link to journal]
The anionic Group 13 NHC analogues
[(CHNDipp)2E]−
(E = B or Ga) display contrasting reactivity towards the titanium imido
complex Cp*TiCl(NtBu)py; the gallium system undergoes salt
metathesis yielding the first example of a titanium gallyl compound.
New group members
New DPhil students Adam Russel (from Imperial
College London), Laura Groom and Junjuda Unruangsri (both former Part II
students in the group) joined the group in October.
New Part II students Nicky Evans and Hannah
Morgan, and also academic visitor
Prof Al Nielson (pictured) from Massey University, New Zealand joined
earlier in September. Welcome to all!
New sulfonamide-supported Group 4
ring-opening polymerization catalysts
Organometallics, 2010, 29, 4171-4188.
[link to journal]
The synthesis, structures, and ring-opening
polymerization (ROP) capability of a wide range of sulfonamide-supported
group 4 amide, alkyl, and alkoxide complexes, varying in sulfonamide
N-substituent, metal, coordination number, and geometry are reported.
Ring-opening polymerization of rac-lactide
by bis(phenolate)amine-supported samarium borohydride complexes
Organometallics,
2010, 29, 3602-3621.
[link to journal]
The synthesis and ring-opening polymerization
(ROP) capability of bis(phenolate)amine-supported samarium borohydride and
amide complexes are reported, together with a comprehensive DFT study of
the reaction mechanism.
M=N
cycloaddition and N-N insertion in the reactions of titanium hydrazido
compounds with alkynes
J. Am. Chem. Soc., 2010, 132,
10484-10497
[link to journal]
A combined experimental and DFT study of the
N-N insertion reactions of diamide-amine supported titanium hydrazides
with alkynes is presented.
Conference news
DPhil students Pei Jen Tiong and Matt Blake
presented some of their work in titanium hydrazide reactivity and
ring-opening polymerization catalysis
at the 24th International Conference on Organometallic Chemistry recently
held in Taipei. Click
here to see Pei Jen's
poster and here for Matt's poster. Congratulations to Pei Jen
for winning a poster prize.
meanwhile, back in Europe...
Philip Mountford presented the opening
key-note lecture at the
3rd Blue Sky Conference on Olefin Polymerisation, Sorrento. His
lecture was entitled "Highly
Active Ethylene Polymerisation Catalysts Derived from Group 4 Imido
Compounds: From Catalyst Discovery to Fundamental Aspects of Reaction Site
Selectivity". Click
here to request a copy of the presentation.
Low-coordinate rare earth complexes of the
asymmetric 2,4-di-tert-butylphenolate ligand prepared by redox
transmetallation/protonolysis reactions and their reactivity towards
ring-opening polymerisation
Dalton Trans., 2010, 39,
6693-6704.
Invited contribution for a Special Issue on "Organo f-element
chemistry".
[link to journal]
New trivalent lanthanide aryloxide complexes
have been prepared by redox transmetallation/protolysis reactions.
The complexes alone were
poorly-controlled initiators for the ROP of rac-lactide, but use of
BnNH2 led to
well-controlled, amine-initiated immortal ROP of rac-lactide.
Dr Andy Schwarz!
28th May and Andy Schwarz successfully defends
his DPhil Thesis entitled "Sulfonamide-supported catalysts for the
ring-opening polymerisation of cyclic esters". External examiner Prof
Manfred Bochmann and internal Dr Simon Aldridge sharing in the victory
feast!
Synthesis,
solid state and DFT structure and olefin polymerization capability of a unique
base-free dimeric methyl titanium dication
Chem. Commun. 2010, 46,
3339-3341.
[link to journal]
Reaction of Cp*Ti{NC(ArF2)NiPr2}Me2
with [Ph3C][B(C6F5)4]
gave the base-free dication [Cp*2Ti2{NC(ArF2)NiPr2}2(μ-Me)2][B(C6F5)4]2
containing two doubly α-agostic bridging methyl groups which is a highly
effective ethylene–propylene polymerization catalyst.
This work was carried out in collaboration
with DSM Research, The Netherlands who have sponsored research in our
group for over 10 years.
Not just good in the lab!
In the
true spirit of mens sana in corpore sano some of the
Mountford group takes to the field in the 2010 Catalyst Cup tournament.
Back row: Mike Cushion, Liban Saleh, Jon
Selby, George Hilton, Richard Scott
Front row: Dan Schofield, Andy Schwarz, Alex
Heath, Lawrence Clark
Synthesis
and ethylene trimerisation capability of new chromium(II) and chromium(III)
heteroscorpionate complexes
Dalton Trans., 2010, 39, 3653-3664.
[link to journal]
A range of N2O-donor
heteroscorpionate complexes were prepared and evaluated for ethylene
trimerisation.
Sulfonamide-supported
aluminum catalysts for the ring-opening polymerization of rac-lactide
Organometallics, 2010, 29,
1246-1260.
[link to journal]
The synthesis, structures, and ring-opening
polymerization (ROP) capability of a wide range of sulfonamide-supported
aluminium alkyl and alkoxide complexes are reported.
Syntheses
and structural diversity of Group 2 and Group 12 tris(pyrazolyl)methane
and zwitterionic tris(pyrazolyl)methanide compounds
Organometallics,
2010, 29,
1174-1190.
[link to journal]
A range of main group tris(pyrazolyl)methane
and tris(pyrazolyl)methanide complexes were reported. The latter
contain rare examples of "naked" sp3 hybridised
carbanions.
Conference
news
Philip Mountford presented a key-note lecture
at the
5th Australian
Organometallics Discussion Meeting, held January 17-20 2010 at the
University of New South Wales, Sydney.
His lecture was entitled "New
Terminal Titanium Hydrazido Complexes: Exploring the Chemistry of the
Ti=N-NR2 Functional Group".
Click
here to request a copy of the presentation.
Dicationic
and zwitterionic catalysts for the amine-initiated, immortal ring-opening
polymerisation of rac-lactide: facile synthesis of amine-terminated,
highly heterotactic PLA
Chem. Commun. 2010, 46, 273-275.
[link to journal]
Dicationic, zwitterionic and “conventional”
yttrium compounds act as catalysts for the primary or secondary
amine-initiated immortal ROP of rac-lactide; amine-terminated, highly
heterotactic poly(rac-lactides) with narrow polydispersities and
well-controlled molecular weights are prepared in this manner.
Single
and double substrate insertion into the Ti=N bonds of terminal titanium
hydrazides
Chem. Commun. 2010, 46,
85-87.
[link to journal]
Nitriles, CO2 and isocyanates
undergo net single or double insertion reactions into the Ti=Nα multiple
bonds of terminal titanium hydrazides. These are the first such examples
of this type of reactivity for any transition metal hydrazide complex.
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