Download Effect of the inclusion of metal ions on the binding properties of a

Supplementary Material (ESI) for New Journal of Chemistry
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique
2001
Letter to: New Journal of Chemistry
Supplementary Material.
Effect of the inclusion of sodium cation on the binding
properties of a switchable diporphyrin receptor.
Donato
Monti,*a
Laura
La
Monica,a
Anita
Scipioni,b
and
Giovanna Mancini.c
a)
Dipartimento
Università
di
di
Roma
Scienze
“Tor
e
Tecnologie
Vergata”,
via
Chimiche,
della
Ricerca
Scientifica s.n.c., I-00133 Rome, Italy.
b)
Dipartimento
di
Chimica,
Università
di
Roma
“La
Sapienza”, Ple. Aldo Moro 3, I-00185 Rome, Italy.
c)
Centro C.N.R. di Studio sui Meccanismi di Reazione,
Dipartimento di Chimica, Università di Roma “La Sapienza”,
Ple. Aldo Moro 3, I-00185 Rome, Italy.
Keywords: CD spectroscopy, host-guest chemistry, podands,
porphyrinoids, supramolecular chemistry.
*) Corresponding Author: phone:
+39 06 7259 4738
fax:
+39 06 7259 4328
E-mail:
[email protected]
Supplementary Material (ESI) for New Journal of Chemistry
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique
2001
Supplementary material.
1
Instrumentation:
H-NMR spectra were recorded with a Bruker
AC 300 P (300 MHz) spectrometer. Chemical shifts are given
in
ppm
relative
spectra
were
to
tetramethylsilane
measured
on
a
(TMS).
Perkin
UV-visible
18
Elmer
Spectrophotometer equipped with a termostatted cell holder.
CD
spectra
were
recorded
on
a
JASCO
J-715
Spectropolarimeter and reported as [nm]/[L mol-1 cm-1].
Mass
spectra
(FAB)
were
recorded
on
a
VG
Quattro
Spectrometer using m-nitrobenzyl alcohol (NBA, Aldrich) as
a matrix in positive ion mode.
Materials: Silica gel 60 (70-230 mesh) was used for column
chromatography. Reagents (Aldrich, Merck or Fluka) were of
the highest grade available and were used without further
purification. Sodium perchlorate (Anhydrous, Aldrich) was
additionally
atmosphere.
vacuum
Solvents
dried,
were
and
dried,
stored
under
distilled
a
dry
and degassed
prior to use, by using standard procedures.S1 Solvents used
for
spectrophotometric
chloroform
Uvasol
measurements,
(Merck),
were
acetonitrile
stored
over
and
activated
molecular sieves.
UV-visible spectroscopic titration: a typical procedure is
as follows: aliquots of titrating solution (1x10-2÷1x10-4
M),
prepared
by
dissolving
the
required
amount
of
the
Supplementary Material (ESI) for New Journal of Chemistry
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique
2001
guests in a freshly prepared stock solution of the free
receptor
1Zn
(1-5x10-5
M),
were
added,
portionwise
via
microsyringe, to a 2.5 mL of the 1Zn stock solution (1 cm
quartz cell, 25.0 °C). The absorbance variation (Q band,
556 nm) was monitored at different concentration of added
guest. The binding constants (K) were calculated by using a
standard
equation
for
A=[1Zn]K[G]/(1+K[G]),
a
1:1
A=A0-Ai;
where
complexation:
=e0-e∞;
[G]
is
the concentration of the added guest. The computer aided
non-linear least square fitting analyses, to give K and 
valueshave been performed with the program Kaleidagraph®
(version
Reading
3.0.4
PA
by
19606,
Abelbeck
USA).
Software,
The
Synergy
experiments
have
Software,
run
in
duplicate and are reproducible within the range of 2÷5%.
Preparations. The free-base porphyrin precursors 1 and 2
were prepared according to published procedures.S2 Syntheses
of porphyrin derivatives 1Zn and 2Zn have been accomplished
by
standard
metalation
proceduresS3
of
1
and
2,
respectively.
Zinc[5-(4-hydroxy-3-methoxyphenyl)-10,15,20-triphenylporphyrinatoyl], 2Zn: In a 50 mL round bottomed flask,
equipped with a reflux condenser, a solution of 100 mg of 2
(
0.15
mmol)
in
25
mL
of
chloroform
was
placed.
The
reaction mixture was brought to reflux temperature and an
excess (2.5 mL) of a saturated zinc acetate methanolic
Supplementary Material (ESI) for New Journal of Chemistry
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique
2001
solution
was
added.
The
progress
of
the
reaction
was
monitored by UV-visible spectroscopy (Soret and Q visible
bands changes). After 2 hours, the mixture was cooled to
room temperature and the solvent removed in vacuo (rotary
evaporator)
to
give
a
cherry-purple
solid
which
was
dissolved in 50 mL of dichloromethane and washed (3x50 mL)
with
brine.
The
organic
phase
was
dried
(Na2SO4),
the
solved stripped off under reduced pressure and the residue,
constituted by virtually pure 2Zn, was further crystallised
from a CH2Cl2/hexane mixture, to give 95 mg (0.13 mmol, 87%
yield)
of
the
title
product
as
bright
cherry-purple
crystals.
1,11-Bis[zinc(2-methoxy-4-(10,15,20-triphenyl-5porphyrinatoyl)-phenoxy)]-3,6,9-trioxaundecane,
1Zn:
The
synthesis has been carried out by following the procedure
employed for the preparation of 2Zn. Starting from 0.18 g
(0.126 mmol) of 1, 0.160 g (0.10 mmol, 84% yield) of 1Zn
were obtained, as a bright purple crystalline solid.
Supplementary Material (ESI) for New Journal of Chemistry
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique
2001
References
S1)
D.D.
Perrin,
Purification
W.L.F.
of
Armarego
Laboratory
and
D.E.
Chemicals,
Perrin
2nd
in
ed.,
Pergamon Press, New York, 1980.
S2)
L. La Monica, D. Monti, G. Mancini, M. Montalti, L.
Prodi, N. Zaccheroni, G. D’Arcangelo and R. Paolesse,
N. J. Chem. 2001, 25, 597.
S3)
P. Bhyrappa and V. Krishnan, Inorg. Chem. 1991, 30,
239.