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<meta content="Dijkstra, H.P." name="eprints.creators_name" />
<meta content="Meijer, M.D." name="eprints.creators_name" />
<meta content="Patel, J." name="eprints.creators_name" />
<meta content="Kreiter, R." name="eprints.creators_name" />
<meta content="van Klink, G.P.M." name="eprints.creators_name" />
<meta content="Lutz, M." name="eprints.creators_name" />
<meta content="Spek, A.L." name="eprints.creators_name" />
<meta content="Canty, A.J." name="eprints.creators_name" />
<meta content="van Koten, G." name="eprints.creators_name" />
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<meta content="allan.canty@utas.edu.au" name="eprints.creators_id" />
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<meta content="2007-10-10 23:38:36" name="eprints.datestamp" />
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<meta content="Design and performance of rigid nanosize multimetallic
cartwheel pincer compounds as lewis-acid catalysts" name="eprints.title" />
<meta content="pub" name="eprints.ispublished" />
<meta content="259901" name="eprints.subjects" />
<meta content="restricted" name="eprints.full_text_status" />
<meta content="Definitive version is available online at http://pubs.acs.org/journals/orgnd7/index.html" name="eprints.note" />
<meta content="Novel strategies for the preparation of rigid cartwheel pincer metal complexes have been
developed. The aromatic backbone of these materials ensures a high rigidity, which is
expected to be important for a high retention when these multimetallic nanosize complexes
are applied as homogeneous catalysts in a nanomembrane reactor. The ligand precursors
C6[C6H3(CH2Y)2-3,5]6 (10, Y = NMe2; 11, Y = SPh; 12, Y = PPh2; 13, Y = pz = pyrazol-1-yl)
have been prepared in high yields from the key intermediate C6[C6H3(CH2Br)2-3,5]6 (9). The
hexakis(pincer) palladium(II) complexes C6[(PdX)-4-C6H2(CH2Y)2-3,5]6 (14, Y = SPh, L =
Cl; 15, Y = PPh2, L = Cl; 16, Y = pyrazol-1-yl, L = OAc; 17, Y = pyrazol-1-yl, L = Cl) have
been prepared via direct electrophilic palladation of the corresponding ligands. The
(tris)pincer ligand C6H3[Br-4-C6H3(CH2NMe2)2-3,5]3-1,3,5 (20) was prepared via a triplecondensation
reaction of 4-bromo-3,5-bis[(dimethylamino)methyl]acetophenone (19). Reaction
of 20 with Pd(dba)2 yielded the tripalladium complex C6H3[(PdBr)-4-C6H3(CH2NMe2)2-3,5]3-
1,3,5 (21). The crystal structure of 21 shows a propeller-like structure with D3 symmetry
and a fixed bromine-bromine distance of 17.4573(4) Å, approximately forming a triangle
with a height of 15.2 Å. These nanosize cartwheel pincer metal complexes based on tridentate
Y,C,Y' pincer ligands have been used as homogeneous Lewis-acid catalysts. Moreover, the
influence of the donor substituent Y on the catalytic activity of cationic mono-Y,C,Y' PdII
complexes as Lewis-acid catalysts in the double Michael reaction between methyl vinyl ketone
and ethyl alpha-cyanoacetate, as a model reaction, has been investigated. It was found that
cationic N,C,N'-type pincer complexes (1a, Y = NMe2; 1b, Y = pz; 1c, Y = pz* =
3,5-dimethylpyrazol-1-yl; 23) were superior to the P,C,P'- and S,C,S'-pincer complexes (1d,
Y = PPh2; 1e, Y = SPh). The nanosize cationic tri-N,C,N' PdII complex 23 was found to have
a catalytic activity per catalytic site in the double Michael reaction of the same order of
magnitude as the monopincer analogue 1a (k = 279 x 10-6 s-1 for 1a vs k = 232 x 10-6 s-1
for 23). The combination of the nanosize dimensions, the catalytic activity, and the high
thermal and air stability makes these complexes excellent candidates for application in a
continuous process in a nanomembrane reactor." name="eprints.abstract" />
<meta content="2001-07" name="eprints.date" />
<meta content="published" name="eprints.date_type" />
<meta content="Organometallics" name="eprints.publication" />
<meta content="20" name="eprints.volume" />
<meta content="14" name="eprints.number" />
<meta content="3159-3168" name="eprints.pagerange" />
<meta content="10.1021/om0101689" name="eprints.id_number" />
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<meta content="Dijkstra, H.P. and Meijer, M.D. and Patel, J. and Kreiter, R. and van Klink, G.P.M. and Lutz, M. and Spek, A.L. and Canty, A.J. and van Koten, G. (2001) Design and performance of rigid nanosize multimetallic cartwheel pincer compounds as lewis-acid catalysts. Organometallics, 20 (14). pp. 3159-3168." name="eprints.citation" />
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cartwheel pincer compounds as lewis-acid catalysts" name="DC.title" />
<meta content="Dijkstra, H.P." name="DC.creator" />
<meta content="Meijer, M.D." name="DC.creator" />
<meta content="Patel, J." name="DC.creator" />
<meta content="Kreiter, R." name="DC.creator" />
<meta content="van Klink, G.P.M." name="DC.creator" />
<meta content="Lutz, M." name="DC.creator" />
<meta content="Spek, A.L." name="DC.creator" />
<meta content="Canty, A.J." name="DC.creator" />
<meta content="van Koten, G." name="DC.creator" />
<meta content="259901 Organometallic Chemistry" name="DC.subject" />
<meta content="Novel strategies for the preparation of rigid cartwheel pincer metal complexes have been
developed. The aromatic backbone of these materials ensures a high rigidity, which is
expected to be important for a high retention when these multimetallic nanosize complexes
are applied as homogeneous catalysts in a nanomembrane reactor. The ligand precursors
C6[C6H3(CH2Y)2-3,5]6 (10, Y = NMe2; 11, Y = SPh; 12, Y = PPh2; 13, Y = pz = pyrazol-1-yl)
have been prepared in high yields from the key intermediate C6[C6H3(CH2Br)2-3,5]6 (9). The
hexakis(pincer) palladium(II) complexes C6[(PdX)-4-C6H2(CH2Y)2-3,5]6 (14, Y = SPh, L =
Cl; 15, Y = PPh2, L = Cl; 16, Y = pyrazol-1-yl, L = OAc; 17, Y = pyrazol-1-yl, L = Cl) have
been prepared via direct electrophilic palladation of the corresponding ligands. The
(tris)pincer ligand C6H3[Br-4-C6H3(CH2NMe2)2-3,5]3-1,3,5 (20) was prepared via a triplecondensation
reaction of 4-bromo-3,5-bis[(dimethylamino)methyl]acetophenone (19). Reaction
of 20 with Pd(dba)2 yielded the tripalladium complex C6H3[(PdBr)-4-C6H3(CH2NMe2)2-3,5]3-
1,3,5 (21). The crystal structure of 21 shows a propeller-like structure with D3 symmetry
and a fixed bromine-bromine distance of 17.4573(4) Å, approximately forming a triangle
with a height of 15.2 Å. These nanosize cartwheel pincer metal complexes based on tridentate
Y,C,Y' pincer ligands have been used as homogeneous Lewis-acid catalysts. Moreover, the
influence of the donor substituent Y on the catalytic activity of cationic mono-Y,C,Y' PdII
complexes as Lewis-acid catalysts in the double Michael reaction between methyl vinyl ketone
and ethyl alpha-cyanoacetate, as a model reaction, has been investigated. It was found that
cationic N,C,N'-type pincer complexes (1a, Y = NMe2; 1b, Y = pz; 1c, Y = pz* =
3,5-dimethylpyrazol-1-yl; 23) were superior to the P,C,P'- and S,C,S'-pincer complexes (1d,
Y = PPh2; 1e, Y = SPh). The nanosize cationic tri-N,C,N' PdII complex 23 was found to have
a catalytic activity per catalytic site in the double Michael reaction of the same order of
magnitude as the monopincer analogue 1a (k = 279 x 10-6 s-1 for 1a vs k = 232 x 10-6 s-1
for 23). The combination of the nanosize dimensions, the catalytic activity, and the high
thermal and air stability makes these complexes excellent candidates for application in a
continuous process in a nanomembrane reactor." name="DC.description" />
<meta content="2001-07" name="DC.date" />
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<h1 class="ep_tm_pagetitle">Design and performance of rigid nanosize multimetallic cartwheel pincer compounds as lewis-acid catalysts</h1>
<p style="margin-bottom: 1em" class="not_ep_block"><span class="person_name">Dijkstra, H.P.</span> and <span class="person_name">Meijer, M.D.</span> and <span class="person_name">Patel, J.</span> and <span class="person_name">Kreiter, R.</span> and <span class="person_name">van Klink, G.P.M.</span> and <span class="person_name">Lutz, M.</span> and <span class="person_name">Spek, A.L.</span> and <span class="person_name">Canty, A.J.</span> and <span class="person_name">van Koten, G.</span> (2001) <xhtml:em>Design and performance of rigid nanosize multimetallic cartwheel pincer compounds as lewis-acid catalysts.</xhtml:em> Organometallics, 20 (14). pp. 3159-3168.</p><p style="margin-bottom: 1em" class="not_ep_block"></p><table style="margin-bottom: 1em" class="not_ep_block"><tr><td valign="top" style="text-align:center"><a href="http://eprints.utas.edu.au/2063/1/om0101689.pdf"><img alt="[img]" src="http://eprints.utas.edu.au/style/images/fileicons/application_pdf.png" class="ep_doc_icon" border="0" /></a></td><td valign="top"><a href="http://eprints.utas.edu.au/2063/1/om0101689.pdf"><span class="ep_document_citation">PDF</span></a> - Full text restricted - Requires a PDF viewer<br />179Kb</td><td><form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/request_doc"><input accept-charset="utf-8" value="2602" name="docid" type="hidden" /><div class=""><input value="Request a copy" name="_action_null" class="ep_form_action_button" onclick="return EPJS_button_pushed( '_action_null' )" type="submit" /> </div></form></td></tr></table><p style="margin-bottom: 1em" class="not_ep_block">Official URL: <a href="http://dx.doi.org/10.1021/om0101689">http://dx.doi.org/10.1021/om0101689</a></p><div class="not_ep_block"><h2>Abstract</h2><p style="padding-bottom: 16px; text-align: left; margin: 1em auto 0em auto">Novel strategies for the preparation of rigid cartwheel pincer metal complexes have been
developed. The aromatic backbone of these materials ensures a high rigidity, which is
expected to be important for a high retention when these multimetallic nanosize complexes
are applied as homogeneous catalysts in a nanomembrane reactor. The ligand precursors
C6[C6H3(CH2Y)2-3,5]6 (10, Y = NMe2; 11, Y = SPh; 12, Y = PPh2; 13, Y = pz = pyrazol-1-yl)
have been prepared in high yields from the key intermediate C6[C6H3(CH2Br)2-3,5]6 (9). The
hexakis(pincer) palladium(II) complexes C6[(PdX)-4-C6H2(CH2Y)2-3,5]6 (14, Y = SPh, L =
Cl; 15, Y = PPh2, L = Cl; 16, Y = pyrazol-1-yl, L = OAc; 17, Y = pyrazol-1-yl, L = Cl) have
been prepared via direct electrophilic palladation of the corresponding ligands. The
(tris)pincer ligand C6H3[Br-4-C6H3(CH2NMe2)2-3,5]3-1,3,5 (20) was prepared via a triplecondensation
reaction of 4-bromo-3,5-bis[(dimethylamino)methyl]acetophenone (19). Reaction
of 20 with Pd(dba)2 yielded the tripalladium complex C6H3[(PdBr)-4-C6H3(CH2NMe2)2-3,5]3-
1,3,5 (21). The crystal structure of 21 shows a propeller-like structure with D3 symmetry
and a fixed bromine-bromine distance of 17.4573(4) Å, approximately forming a triangle
with a height of 15.2 Å. These nanosize cartwheel pincer metal complexes based on tridentate
Y,C,Y' pincer ligands have been used as homogeneous Lewis-acid catalysts. Moreover, the
influence of the donor substituent Y on the catalytic activity of cationic mono-Y,C,Y' PdII
complexes as Lewis-acid catalysts in the double Michael reaction between methyl vinyl ketone
and ethyl alpha-cyanoacetate, as a model reaction, has been investigated. It was found that
cationic N,C,N'-type pincer complexes (1a, Y = NMe2; 1b, Y = pz; 1c, Y = pz* =
3,5-dimethylpyrazol-1-yl; 23) were superior to the P,C,P'- and S,C,S'-pincer complexes (1d,
Y = PPh2; 1e, Y = SPh). The nanosize cationic tri-N,C,N' PdII complex 23 was found to have
a catalytic activity per catalytic site in the double Michael reaction of the same order of
magnitude as the monopincer analogue 1a (k = 279 x 10-6 s-1 for 1a vs k = 232 x 10-6 s-1
for 23). The combination of the nanosize dimensions, the catalytic activity, and the high
thermal and air stability makes these complexes excellent candidates for application in a
continuous process in a nanomembrane reactor.</p></div><table style="margin-bottom: 1em" cellpadding="3" class="not_ep_block" border="0"><tr><th valign="top" class="ep_row">Item Type:</th><td valign="top" class="ep_row">Article</td></tr><tr><th valign="top" class="ep_row">Additional Information:</th><td valign="top" class="ep_row">Definitive version is available online at http://pubs.acs.org/journals/orgnd7/index.html</td></tr><tr><th valign="top" class="ep_row">Subjects:</th><td valign="top" class="ep_row"><a href="http://eprints.utas.edu.au/view/subjects/259901.html">250000 Chemical Sciences > 259900 Other Chemical Sciences > 259901 Organometallic Chemistry</a></td></tr><tr><th valign="top" class="ep_row">Collections:</th><td valign="top" class="ep_row">UNSPECIFIED</td></tr><tr><th valign="top" class="ep_row">ID Code:</th><td valign="top" class="ep_row">2063</td></tr><tr><th valign="top" class="ep_row">Deposited By:</th><td valign="top" class="ep_row"><span class="ep_name_citation"><span class="person_name">Prof Allan J Canty</span></span></td></tr><tr><th valign="top" class="ep_row">Deposited On:</th><td valign="top" class="ep_row">11 Oct 2007 10:38</td></tr><tr><th valign="top" class="ep_row">Last Modified:</th><td valign="top" class="ep_row">01 Feb 2008 15:00</td></tr><tr><th valign="top" class="ep_row">ePrint Statistics:</th><td valign="top" class="ep_row"><a target="ePrintStats" href="/es/index.php?action=show_detail_eprint;id=2063;">View statistics for this ePrint</a></td></tr></table><p align="right">Repository Staff Only: <a href="http://eprints.utas.edu.au/cgi/users/home?screen=EPrint::View&eprintid=2063">item control page</a></p>
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