146
M.S. Refat, T. Sharshar / Journal of Molecular Structure 1016 (2012) 140–146
[2] F. Hueso-Urena, J. Inorg. Biochem. 94 (2003) 326.
900
800
700
600
500
400
300
[3] M.S. Refat, S.A. El-Korashy, A.S. Ahmed, Spectrochim. Acta 71A (2008) 1084.
[4] M.S. Refat, N.M. El-Metwaly, J. Mol. Str. 988 (1–3) (2011) 118.
[5] V.T. Yilmaz, F. Yilmaz, E. Guney, O. Buyukgungor, J. Coord. Chem. 64 (1) (2011)
159.
[6] F. Yilmaz, V.T. Yilmaz, E. Soyer, O. Buyukgungor, Inorg. Chim. Acta 363 (13)
(2010) 3165.
[7] V.T. Yilmaz, E. Soyer, O. Buyukgungor, J. Organometal. Chem. 694 (20) (2009)
3306.
[8] J.S. Casas, E.E. Castellans, M.D. Louce, J. Ellena, A. Sanchez, J. Sordo, C. Taboada,
J. Inorg. Biochem. 11 (2006) 1858.
[9] J.S. Casas, M.S. Garcia-Tasende, C. Maichel-Mossmer, M.C. Rodriguez-Argüelles,
A. Sanchez, J. Sordo, A. Vazquez-Lopez, S. Pinelli, P. Lunghi, R. Albertini, J. Inorg.
Biochem. 62 (1996) 41.
[10] U. Koch, B. Attenni, S. Malancona, S. Colarusso, I. Conte, M.D. Filippo, S. Harper,
B. Pacini, C. Giomini, S. Thomas, I. Incitti, L. Tomei, R.D. Francesco, S. Altamura,
V.G. Matassa, F. Narjes, J. Med. Chem. 49 (2006) 1693.
[11] H.C. Garcia, F.B. De Almeida, R. Diniz, M.I. Yoshida, L.F.C. De Oliveira, J. Coord.
Chem. 64 (2011) 1125.
300
350
400
450
500
550
600
Molecular Weight
Fig. 9. The mean lifetime as a function of the molecular weight of metal complex.
[12] H.C. Garcia, F.B. De Almeida, R. Diniz, M.I. Yoshida, L.F.C. De Oliveira, J. Mol. Str.
978 (2010) 79.
[13] V.T. Yilmaz, F. Yilmaz, H. Karakaya, O. Buyukgungor, W.T.A. Harrison,
Polyhedron 25 (2006) 2829.
[14] F. Yilmaz, V.T. Yilmaz, E. Bicer, O. Buyukgungor, J. Coord. Chem. 60 (2007) 777.
[15] F. Yilmaz, V.T. Yilmaz, H. Karakaya, O. Buyukgungor, Zeit. für Naturfors. 63B
(2008) 134.
[16] M.S. Aksoy, V.T. Yilmaz, O. Büyükgüngör, J. Coord. Chem. 62 (2009) 3250.
[17] V.T. Yilmaz, M.S. Aksoy, O. Sahin, Inorg. Chim. Acta 362 (2009) 3703.
[18] E. Soyer, F. Yilmaz, V.T. Yilmaz, O. Buyukgungor, W.T.A. Harrison, J. Inorg.
Organomet. Poly. Mater. 20 (2010) 320.
[19] A. Ashnagar, N.G. Naseri, B. Sheeri, Chin. J. Chem. 25 (2007) 382.
[20] J.N. Delgado, W.A. Remers, J.B. Lippincott (Eds.), Wilson and Gisvold’s
Textbook of Organic Medicinal Pharmaceutical Chemistry, ninth ed., L.
Williams & Wilkins, Philadelphia, 1991, p. 39. 341, 376.
[21] D.A. Williams, T.L. Lemke, Foye’s Principles of Medicinal Chemistry, fifth ed.,
Lippincott Williams & Wilkins, Philadelphia, 2002. pp. 377–378.
[22] D.M. Schrader, Y.C. Jean, Positron and Positronium Chemistry, Studies in
Physical and Theoretical Chemistry, vol. 57, Elsevier, Amsterdam, 1986.
[23] W. Brandt, A. Dupasquier (Eds.), Positron Solid-State Physics, North-Holland,
Amsterdam, 1983.
The order of I2 values of metal complexes is Bi > Sb > Sn. The rela-
tively low value of I2 observed for the Sn(II) complex could be
attributed to its four-electrons donor ligand compared with the
six-electrons donor of Sb(III) and Bi(III) complexes. On the other
hand, the difference of the molar ratio of metal-to-ligand and var-
ious structures of Sn(II), Sb(III) and Bi(III) complexes may affect the
Ps formation (I2). The smaller I2 value of Sb(III), 24.1%, than that of
Bi(III), 32.4%, may be due to the high atomic weight of Bi which in-
creases the electron-donor powerful. The results also show that the
complexation of the HL ligand with Sn(II), Sb(III) and Bi(III) metals
increases the I3 values because it changes the open structure of the
HL ligand and clusters some of smaller voids.
The two lifetime components,
lation of o-Ps indicate that there are two types of vacant with dif-
ferent sizes. The results indicate that the 2 and 3 values of ligand
s2 and s3, ascribed to the annihi-
s
s
are comparable with those values of its metal complexes in spite of
its open structure. This is may be due to the different electron-do-
nor places in each case. To study the molecular weight dependence
of PAL parameters in the samples of metal complexes, the mean
lifetime was calculated using Eq. (1). Fig. 9 shows the variation
of sm as a function of molecular weight of the samples of metal
complexes. The dependence of PAL parameters on the molecular
weight was reported in literature [26]. The results reveal that there
is a positive linear correlation between the sm and the complex
molecular weight. This is because the mass fraction of the donor
component in complex is low for lower molecular weight that
causing a lower fraction of positrons annihilating in that part of
the complex as previously reported [26].
[24] J.C. Machado, G.M. de Lima, F.C. Oliveira, I.M. Marzano, Chem. Phys. Lett. 418
(2006) 292.
[25] A. Marques-Netto, C.F. Carvalho, C.A. Alves de Carvalho, R.D. Sinisterra, H.F.
Brito, J.C. Machado, Chem. Phys. Lett. 333 (2001) 371.
[26] A.M.A. El-Sayed, H.F.M. Mohamed, A.A.A. Boraei, Radiat. Phys. Chem. 58 (2000)
791.
[27] T. Sharshar, M.L. Hussein, Nucl. Instr. Methods A 546 (2005) 584–590.
[28] J. Kansy, Nucl. Instr. Methods A 374 (1996) 235–244.
[29] W.J. Geary, Coord. Chem. 7 (1971) 81.
[30] M.S. Refat, J. Mol. Str. 742 (1–3) (2007) 24.
[31] M.S. Refat, N.M. El–Metwaly, J. Mol. Str. 988 (2011) 111.
[32] N.N. Greenwood, A. Earnshaw, Chemistry of the Elements, Pergamon, Oxford,
1984. p. 98.
[33] J.E. Macintyre, Dictionary of Inorganic Compounds, Chapman & Hall, 1992.
[34] N.N. Greenwood, A. Earnshaw, Chemistry of Elements, second ed.,
Butterworth, Heinemann, 1997.
[35] The Merck Index, 13th edition.
[36] M.S. Silberberg, Chemistry: The Molecular Nature of Matter and Change, fourth
ed., McGraw-Hill Higher Education, Boston, MA, 2006.
[37] D.R. Lide, CRC Handbook of Chemistry and Physics, 83rd ed., CRC Press, Boca
Raton, FL, 2002. p 4:132.
References
[1] Encyclopædia Britannica, 11th ed. Cambridge University Press.