The crystal structure of methylene blue pentahydrate

Abstract

The crystal structure of methylene blue, 3,7-bisdimethylaminophenazothionium chloride pentahydrate, was determined by direct methods from single-crystal X-ray diffraction data. C16HIsN3SC1.5H20 crystallizes in the monoclinic system, space group e2x/c, with a= 9"646 (9), b= 31.106 (17), c= 6.992 (2) /~,, fl= 96.70 (6). The structure was refined by full-matrix least-squares calculations to R= 0"057. The dye molecules are essentially planar, with twenty molecules of water of hydration per unit cell, forming an interesting hydrogen-bonding network through the lattice. Positions for C, N, S, O, and C1 atoms were determined from Fourier electron-density maps. Hydrogen atom positions were refined from a clathrate ice-like model.

Manifestation of intermolecular interactions in FTIR spectra of methylene blue molecules

“…A special characteristic of calculations is to obtain data only for the equilibrium configuration MB + . After optimization there is a uniform distribution of the electron density over the whole MB molecule [8,39,66]. This configuration of MB + is characterized by the absence of a specific region of excess charge localization.…”

“…MB has ionic form MB + in water [6][7][8][9][10]. The formation of dimers and higher order aggregates, or H-aggregates, from the ionic form MB + is typical for MB in water solution [11,12].…”

“…It has a number of resonance structures (Fig. 1, left) [6][7][8]. The domination of one of them (or more) is determined by the type of solvent and reactivity of the environment (organic molecules, inorganic crystals, etc.…”

“…In MB case they are hydrochlorides. In such cases it is important to take into account the effect of intermolecular interactions in dye-dye and dye-environment systems [8,13,[16][17][18][19][20][39][40][41][42][43][44].…”

Lignin selective dyes: quantum-mechanical study of their characteristics

“…From the crystal data about the Acridine Orange cation (Obendorf et al 1976;Reddy et al 1979;Mattia et al 1984Mattia et al , 1995Kuban et al 1985;Gordon et al 2003), the Proflavine cation (Jones and Neidle 1975;Shieh et al 1980Shieh et al , 1982Swaminathan et al 1982;Aggarwal et al 1984;Ara and El Bahij 2004;Varga et al 2007), Methylene Blue (Marr et al 1973;Kahn-Harari et al 1973;Endres et al 1977;Snaathorst et al 1981;Enescu et al 2000;Sours et al 2002;Kavitha et al 2004;Li et al 2005;Soneta and Miyamura 2006;Raj et al 2007), Eosin (Harrison et al 2007), Rhodamine B (Fujii et al 1995;Nishikiori and Fujii 1997;Soneta et al 2006), Ethyl Rhodamine G (Wang et al 1997;Fun et al 1997;Liu et al 1998;Adhikesavalu et al 2001;Zhang et al 2001), Para-rosaniline (Koh and Eriks 1971;Liu et al 2002;Xie 2008), and Crystal Violet (Spangler et al 1989;Lovell et al 1999;Lacour et al 2002;Soneta et al 2006), as well as the substituted 1-phenyl-azo-2-naph...…”