V.E. de Oliveira et al. / Journal of Molecular Structure 936 (2009) 239–249
249
2.841(8), 2.774(10), 2.744(9) and 2.811(10) Å, respectively. As can
be seen in Fig. 5b; the metal is coordinated by four nitrogen atoms
of different TDCMSQ units in a complex geometry, and the M–N
distances are 2.928(12), 2.947(12), 2.859(11) and 2.934(11) Å for
N1, N2, N3 and N4, respectively. The oxocarbon rings are involved
raine species, giving rise to a one-dimensional design perpendic-
ular to the a axis.
Acknowledgments
in
p
-packing interaction along the crystallographic a axis, and in
The authors thank to CNPq, CAPES, FAPEMIG (PRONEX 526/07,
CEX 1812/07 and CEX 4911-5.02/07) and FINEP (PROINFRA 1124/
06) for financial support and to LDRX (Instituto de Física – Univer-
sidade Federal Fluminense) for X-ray facilities.
the b axis the molecule extends infinitely through the two oxygen
atoms which are in bridging in a monoatomic fashion between the
metal sites. The BaABa distance is ca. 4.87(1) Å, implying in a large
interplanar distance, and the centroid–centroid distance ca.
3.785 Å, which is short; these results demonstrate the
interaction, giving rise to a bi-dimensional chain (Figs. 6b and
p-packing
Appendix A. Supplementary data
S11b, c).
Supplementary data associated with this article can be found, in
Some of the compounds did not yield single crystals suitable for
X-ray diffraction; the X-ray powder diffraction for the TDCMSQ
and CDCMSQ-alkalis compounds were obtained and are displayed
in Figs. S12 and S13. The simulated diffractograms of 1,3-alkalis are
almost different in all diffraction patterns (Fig. S12), suggesting
that the compounds are not isostructural to Ca and Ba. On the
other hand, for 1,2-compounds the diffraction patterns suggest
the K and Rb derivatives are isostructural, whereas the other com-
pounds are not related by crystal packing. Comparison of experi-
mental and simulated diffraction patterns of Na [36,37] and Cu
[12] 1,2- compounds indicate that these species are also not iso-
structural (Fig. S13).
References
[1] S-Y. Park, K. Jun, S-W. Oh, Bull. Korean Chem. Soc. 26 (2005) 428.
[2] B.B. Koleva, T. Kolev, R.W. Seidel, M. Spiteller, H. Mayer-Figge, W.S. Sheldrick, J.
Phys. Chem. A 113 (2009) 3088.
[3] B.B. Koleva, T. Kolev, R.W. Seidel, H. Mayer-Figge, M. Spiteller, W.S. Sheldrick, J.
Phys. Chem. A 112 (2008) 2899.
[4] T. Kolev, H. Mayer-Figge, R.W. Seidel, W.S. Sheldrick, M. Spiteller, B.B. Koleva, J.
Mol. Struct. 919 (2009) 246.
[5] J.G.S. Lopes, L.F.C. de Oliveira, H.G.M. Edwards, P.S. Santos, J. Raman Spectrosc.
35 (2004) 131.
[6] J.G.S. Lopes, F.A. Farani, L.F.C. de Oliveira, P.S. Santos, J. Raman Spectrosc. 37
(2006) 142.
[7] N.S. Gonçalves, L.K. Noda, A.M.P. Neto, P.S. Santos, S.R. Mutarelli, O. Sala, J. Mol.
Struct. 645 (2002) 185.
4. Conclusions
[8] C.C. Corrêa, R. Diniz, L.H. Chagas, B.L. Rodrigues, M.I. Yoshida, W.M. Teles, F.C.
Machado, L.F.C. de Oliveira, Polyhedron 26 (2007) 989.
[9] C.C. Corrêa, R. Diniz, L.H. Chagas, B.L. Rodrigues, M.I. Yoshida, Teles, W.M., F.C.
Machado, H.G.M. Edwards, L.F.C. de Oliveira, Vib. Spectrosc. 45 (2007) 82.
[10] A.L. Tatarets, I.A. Fedyunyaeva, E. Terpetschnig, L.D. Patsenker, Dyes Pig 64
(2005) 125.
[11] R. West, Oxocarbons, Academic Press, London, 1980.
[12] C. Pena, A.M. Galibert, B. Soula, P.-L. Fabre, G. Bernardinelli, P. Castan, J. Chem.
Soc. Dalton Trans. (1998) 239.
[13] G. Farnia, B. Lunelli, F. Marcuzzi, G. Sandonà, J. Electroanal. Chem. 404 (1996)
261.
[14] P.-L. Fabre, C. Pena, A.M. Galibert, B. Soula, G. Bernardinelli, B. Donnadieu, P.
Castan, Can. J. Chem. 78 (2000) 280.
[15] K.-Y Law, F.C. Bailey, Can. J. Chem. 64 (1986) 2267.
[16] C.E. Silva, R. Diniz, B.L. Rodrigues, L.F.C de Oliveira, J. Mol. Struct. 831 (2007)
187.
[17] (a) B. Lunelli, R. Soave, R. Destro, Phys. Chem. Chem. Phys. 1 (1999) 1469;
(b) B. Lunelli, P. Roversi, E. Ortoleva, R. Destro, J. Chem. Soc. Faraday Trans. 92
(1996) 3611.
[18] T.A. Blinka, R. West, Tetrahedron Lett. 24 (1983) 1567.
[19] K.Y. Law, J. Phys. Chem. 99 (1995) 9818.
[20] A. Treibs, K. Jacob, Angew. Chem. Int. Ed. Engl. 4 (1965) 694.
[21] R.W. Bigelow, H.J. Freund, J. Chem. Phys. 107 (1986) 159.
[22] P.-L. Fabre, A.M. Galibert, B. Soula, F. Dahan, P. Castan, J. Chem. Soc. Dalton
Trans. (2001) 1529.
A comprehensive synthetic and spectroscopic study of the 1,3-
and 1,2-squaraine compounds has been undertaken. The study
about the reaction process can contribute to explain some details
about the synthetic route, providing a more efficient procedure
to obtain such compounds; although the procedure is well known,
it was not applied to squaraines. The compounds are very stable,
mainly due to the ring stability; this stability can be verified
through thermal analysis, since the observed temperature for the
beginning of degradation is near to 400 °C. 13C RMN analysis shows
that the carbons from the oxocarbon ring of TDCMSQ-Na are more
shielded than for CDCMSQ-Na squaraine, which strongly suggests a
more remarkable electronic delocalization over the oxocarbon ring
for the 1,3-squaraine. This fact suggests higher molecular symme-
try for the 1,3-compound when compared to the 1,2-species, tak-
ing into account only the results obtained in solution. Another
interesting feature concerning such molecules is the position of
the substituent modifies its spectroscopic characteristics, as for in-
stance the energy involved in the electronic transitions. The alkalis
compounds obtained in this work have showed no significant
changes in the vibrational spectra; all of them are coordination
by the nitrogen atoms, as suggested by the vibrational spectra.
Analyzing the series containing alkali metals (from Na, K, Rb, Mg,
Ca, Sr, Ba and tetrabutylammonium cations), the replacement of
the metallic ions has shown to be more difficult for the 1,3-com-
pounds; this difficulty can be justified by a major stability of this
structure containing Na cations, which is evidenced by the elec-
tronic and NMR spectra.
[23] B. Oswald, L. Patsenker, J. Duschl, H. Szmacinski, O.S. Wolfbeis, E. Terpetschnig,
Bioconjug. Chem. 10 (1999) 925.
[24] V.E. de Oliveira, Master Thesis, Universidade Federal de Juiz de Fora
(2007).
[25] V.E. de Oliveira, M.C.R. Freitas, R. Diniz, M.I. Yoshida, N.L. Speziali, H.G.M.
Edwards, L.F.C. de Oliveira, J. Mol. Struct. 881 (2008) 57.
[26] COLLECT, Enraf-Nonius, Nonius BV, Delft, The Netherlands 1997–2000.
[27] A.J.M. Duisenberg, J. Appl. Cryst. 25 (1992) 92.
[28] A.J.M. Duisenberg, L.M.J. Kroon-Batenburg, A.M.M. Schreurs, J. Appl. Cryst. 36
(2003) 220.
[29] G. M. Sheldrick; SHELXL-97 - A Program for Crystal Structure Refinement, 97-
2; University of Goettingen: Germany (1997).
The X-ray diffraction analysis for the 1,3-compound containing
Ca and Ba ions has shown both metals are coordinated in a differ-
ent way. In the barium case, the metal is coordinated to five water
molecules, being two of them in a monodentate coordination
bridging two Ba atoms; the coordination sphere is completed by
four nitrogen atoms of different squaraine species, and the coordi-
nation sphere around the Ba site gives rise to a three-dimensional
polymeric structure. On the other hand, the calcium site is coordi-
nated by six water molecules and two CN groups of different squa-
[30] A.C. Larson, Crystallogr. Comp. (1970) 291.
[31] R.H. Blessing, Acta Cryst. A51 (1995) 33.
[32] L.J. Farrugia, J. Appl. Cryst. 30 (1997) 565.
[33] C.F. Macrae, P.R. Edgington, P. McCabe, E. Pidcock, G.P. Shields, R. Taylor, M.
Towler, J. Van de Streek, J. Appl. Cryst. 39 (2006) 453.
[34] R. Diniz, L.R.V. Sá, B.L. Rodrigues, M.I. Yoshida, N.L. Speziali, H.G.M.
Edwards, L.F.C. de Oliveira, Inorg. Chim. Acta 359 (2006) 2296.
[35] S.L. Georgopoulos, R. Diniz, M.I. Yoshida, N.L. Speziali, H.F. Santos, G.M.A.
Junqueira, L.F.C. de Oliveira, J. Mol. Struct. 794 (2006) 63.
[36] B. Lunelli, M. Monari, A. Bottoni, J. Phys. Chem. A 105 (2001) 2257.
[37] V. Busetti, B. Lunelli, J. Phys. Chem. 90 (1986) 2052.