Crystallization of Mo–EDTA complex based solids: Molecular insights

The paper reports synthesis and structural elucidation of three new 2:1 molybdenum–EDTA complex based solids: [{Na2(H2O)6}{Mo2O6(H2EDTA)}]·2H2O (1), [{Na4(H2O)8}{Mo2O6(EDTA)}] (2) and [(H2TEMED)Mo2O6(H2EDTA)]·H2O (3). Retrosynthesis of the phases crystallized from the system Na2H2EDTA·2H2O−Na2MoO4·H2O or TEMED-MoO3 provides molecular insights by interpreting the crystal packing in terms of the intermolecular interactions between tectons. 1 and 2 are examples of concentration-dependent crystallization. 3 is the first example based on Mo–EDTA with organic as counter cation. In 1 and 2, the Mo–EDTA complex is coordinated through water-bridged sodium hydrates while in 3 the 2:1 complex interacts with organic counter cation through hydrogen bonding. Crystal data: 1, Monoclinic, space group P21/c, a = 8.5086(9) Å, b = 11.5536(12) Å, c = 13.3844(14) Å,  = 92.713(2)°, Z = 4; 2, Monoclinic, space group P21/c, a = 11.892(8) Å, b = 6.587(5) Å, c = 17.155(12) Å,  = 108.794(11)°, Z = 4; 3, Monoclinic, space group P2/c, a = 14.549(4) Å, b = 6.9153(17) Å, c = 15.471(4) Å,  = 112.843(4)°, Z = 2.

► Formation of new 2:1 Mo–EDTA solids.
► Structural features-hydrated sodium aggregation, pseudopolymoprhs.
► Influence of pH and concentration on the growth of solids.
► Formation of new Mo–EDTA complex based on TEMED as organic cation.
► Due to better chelating ability of EDTA, solids are stable over wider pH & T range.