Synthesis, Crystal Structures And Properties Of The Chiral Coordination Compounds Constructed From Amino Acid Derivates

Recently, the rational design and synthesis of chiral metal–organic frameworks (MOFs)has been highly concerned in the field of crystal engineering, coordination chemistry,supramolecular chemistry and materials chemistry, not only because their aesthetic andtopological interest but also owing to their promising applications in asymmetric catalysis,enantioselective separation, magnetism, ferroelectric properties, and nonlinear opticalapplications. This paper summarizes the research advances of chiral complexes thatconstructed from chiral and achiral ligends, and a series of coordination polymers constructedfrom N-benzoyl-L-glutamic acid (H2bzgluO) and N-tosyl-L-phenylalanine (Htsphe) have beensynthesized, and the crystal structures and properties of these complexes have also beenstudied.First, seven complexes constructed from N-benzoyl-L-glutamic acid:[Cu2(bzgluO)2(2,2′-bipy)2]·7H2O (1);[Cu(bzgluO)(2,4′-bipy)2(H2O)]n·2nH2O (2);[Cu2(bzgluO)2(4,4′-bipy)2]n(3);[Cu2(bzgluO)2(bpe)2]n·5nH2O (4);[Zn(bzgluO)(bpp)]n·1.75nH2O (5);[Zn(bzgluO)(4,4′-bipy)0.5]n(6);[Ag2(Hbzgluo)2(bpe)2]·4nH2O (7);(H2bzgluO=N-benzoyl-L-glutamic acid;2,2′-bipy=2,2′-bipyridine;2,4′-bipy=2,4′-bipyridine;4,4′-bipy=4,4′-bipyridine;bpp=1,3-bis(4-pyri-dyl)propane; bpe=1,2-bis(4-pyridyl)ethane). These complexes have beencharacterized by using single-crystal X-ray diffraction, infrared spectra, elemental analysis,thermogravimetric analysis.The X-ray structural determination indicates that complex1crystallizes in the orthorhombic space group P212121, the adjacent Cu(II) cations are bridged by-and-carboxyl groups of two bzgluO2-dianions to form a dinuclear structure, it is important tonote that a1D right-handed helical water chain formed through lattice water molecules.Complex2crystallizes in the triclinic space group P1, Cu(II) cations are bridged by-and-carboxyl groups of bzgluO2-dianions to form a1D chain structure, the adjacent chains arefurther consolidated by intermolecular hydrogen bonds to generate2D supramolecularnetwork. Complex3crystallizes in the monoclinic space group P21，Cu(II) cations are bridgedby-and-carboxyl groups of bzgluO2-dianions to form a [Cu(bzgluO)]∞layer parallel to the ab plane, it should be noted that these layers are stacked in ABAB sequence alongthe c direction and further pillared by the4,4’-bipy ligands to link the2D layers into a3Dnetwork. Complex4crystallizes in the monoclinic space group P21, Cu(II) cations are bridgedby-and-carboxyl groups of bzgluO2-dianions to form a [Cu(bzgluO)]∞layer parallel tothe ab plane and further through the bpe ligands to link the2D layers into a3D porousnetwork, and unique octameric water clusters is encapsulated in the3D porous framework.Complex5crystallizes in the monoclinic space group C2, Zn(II) cations are bridged by-and-carboxyl groups of bzgluO2-dianions to form a1D left-handed helical chain structurealong the b direction, which is further interconnected by the bpp molecules along the cdirection form a2D wave-like structure, it should be note that these2D sheets are stacked inan ABAB fashion along the a direction. Complex6crystallizes in the tetragonal space groupP43212, Zn(II) cations are bridged by-and-carboxyl groups of bzgluO2-dianions to form a[Zn(bzgluO)]∞layer parallel to the ab plane, it should be noted that these layers are stacked inABAB sequence along the c direction, and further pillared by the4,4’-bipy ligands link the2Dlayers into a3D network. Complex7crystallizes in the monoclinic space group C2, theadjacent Ag(I) cations and two different bzgluO2-dianions form a binuclear unit[Ag2(HbzgluO)2], these binuclear units are bridged by bpe molecules form a1D double chainstructure, which is further connected by intermolecular hydrogen bonds to generate3Dsupramolecular network.The structural diversities of complexes1-7indicate that the versatile coordination modes of the bzgluO2-dianions, difference N-donor ancillary ligands, as well asthe nature of the metal cations play crucial roles in modulating structures of the coordinationcomplexes. Additionally, magnetic properties study indicates that complex1show differentferromagnetic and antiferromagnetic interactions whth the change of temperature, complexes2show ferromagnetic interactions, and complex3show antiferromagnetic interactions. Thesolid-state photoluminescent properties indicates that complex5-7are all potential fluorescentmaterials.Second, two complexes constructed from N-tosyl-L-phenylalanine:[Cu(tsphe)2(2,2′-bipy)]·2ts (8);[Zn(tsphe)2(2,4′-bipy)2](9);(Htsphe=N-tosyl-L-phenylalanine;2,2′-bipy=2,2′-bipyridine;2,4′-bipy=2,4′-bipyridine). The two complexes have been characterized by using single-crystal X-ray diffraction, infrared spectra, elementanalysis,thermogravimetric analysis.The X-ray structural determination indicates that complex8crystallizes in theorthorhombic space group C2221and exhibits monomolecular structures. Complex9crystallizes in the monoclinic space group P21and exhibits monomolecular structures, whichis further connected by intermolecular hydrogen bonds to generate1D supramolecularnetwork. Additionally, the solid-state photoluminescent properties indicates that complex9ispotential fluorescent material.