Mechanism of Nonlinear Optical Enhancement and Supramolecular Isomerism in 1D Polymeric Zn(II) and Cd(II) Sulfates with Pyridine-4-aldoxime Ligands

Abstract

Interaction of zinc(II) and cadmium(II) sulfates with pyridine-4-aldoxime (4-pyao) and pyridine-4amidoxime (4-pyamo) ligands resulted in four 1D metal− organic materials (MOMs) with identical composition, [M(SO 4 )A 2 (H 2 O) 2 ] n , where M = Zn(II), A = 4-pyao for 1, M = Cd(II), A = 4-pyao for 2, M = Zn(II), A = 4-pyamo for 3, M = Cd(II), A = 4-pyamo for 4, and mononuclear [Zn(SO 4 )(4-pyamo) 2 (H 2 O) 3 ] 5. New coordination polymers represent the mixed-ligand supramolecular isomers different by the twisting of two pyridine-4-oxime ligands in the metal coordination environments, and crystallizing in the different space groups.Conformational preferences and nonlinear optical properties of the 4-pyao and 4-pyamo complexes were investigated using density functional theory. Spectral properties of 1−3 have been also evaluated. The solid-state emission of 1D polymers 1−3 appears to be ligand-based, as the positions of the emission maxima remain practically unchanged from free ligand to complexes. The enhancement of luminescence and twophoton absorption in polymers in comparison with the pure ligands is attributed to the chelation of the ligand to the metal center. The detailed mechanism of this enhancement upon complex formation is analyzed and can be used in future design of metal−organic nonlinear optical materials.

Confirming the Molecular Basis of the Solvent Extraction of Cadmium(II) Using 2-Pyridyl Oximes through a Synthetic Inorganic Chemistry Approach and a Proposal for More Efficient Extractants

“…Complexes 2 and 4·2EtOH are the first structurally characterized Cd(II) complexes with 3paoH and dapdoH 2 ligands, respectively. Compounds 1 and 3 join a small family of structurally characterized Cd(II) complexes of 2paoH and 4paoH [ 55 , 56 , 57 , 58 , 59 , 60 ], mainly reported by Fonari’s group in a series of excellent crystal engineering studies. The 2paoH complexes reported are [Cd(O 2 CMe) 2 (2paoH) 2 ] [ 50 ], [Cd 2 (suc)(2paoH) 4 (H 2 O) 2 ]](BF 4 ) 2 [ 56 ], {[Cd(suc)(2paoH) 2 ]} n [ 56 ], [Cd(HCO 2 ) 2 (2paoH) 2 ] [ 59 ], {[Cd(1,4-bdc)(2paoH)]·1.5DMF} n [ 59 ], {[Cd(SO 4 )(2paoH)(H 2 O)]} n [ 59 ], {[Cd(fum)(2paoH) 2 ]} n [ 60 ], {[Cd(1,3-bdc)(2paoH)]} n [ 60 ], where suc 2− is the succinate(-2) ligand, 1,4-bdc 2- is the 1,4-benzenedicarboxylate(-2) ligand, fum 2− is the fumarate(-2) ligand and 1,3-bdc 2- is the 1,3-benzedicarboxylate(-2) ligand.…”

“…In all these complexes, the 2paoH molecule behaves as a N,N′-bidentate chelating (1.011) ligand. The 4paoH Cd(II) complexes reported are {[Cd(mal)(4paoH)(H 2 O)]} n [ 56 ], {[Cd(adi)(4paoH) 2 ]·DMF} n [ 56 ], {[Cd(SO 4 )(4paoH) 2 (H 2 O) 2 ]} n [ 57 ], [Cd 2 (O 2 CMe) 4 (4paoH) 4 ]·4H 2 O [ 58 ], [Cd(O 2 CMe) 2 (4paoH) 3 ]·3H 2 O [ 58 ], {[Cd(1,3-bdc)(4paoH)(H 2 O) 2 ]·DMF·H 2 O} n [ 60 ], {[Cd(1,4-bdc)(4paoH) 2 (H 2 O)]·DMF} n [ 60 ] and {[Cd(1,4-bdc)(4paoH) 2 ]·DMF} n [ 60 ], where mal 2− is the malonate(-2) ligand and adi 2− is the adipate(-2) ligand. As in 3, in all of the just mentioned complexes, 4paoH behaves as an N(pyridyl) [1.010] monodentate ligand.…”

Multifunctional Zn(ii)/Cd(ii) metal complexes for tunable luminescence properties and highly efficient dye-sensitized solar cells

“…The d 10 metal complexes have gained intensive attention because of relatively low-cost, intriguing structures and adequate electron transport, which are advantageous to enhance the luminescence efficiency. 20,21 On the basis of the above considerations, we aim to synthesize d 10 metal complexes with strong absorption in ultraviolet and blue-violet light region, in order to replace noble metal complexes (metal osmium(II), platinum(II) and ruthenium(II) MCCs doped semiconductors) as co-sensitizers. [22][23][24] Herein, we report the design and synthesis of two new d 10 metal complexes, [Zn(3-qlc) 2 ] n (Zn1), [Cd(3-qlc) 2 ] n (Cd1).…”

Theoretical Insights into the Tuning of Metal Binding Sites of Paddlewheels in rht‐Metal–Organic Frameworks

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Metal-organic frameworks (MOFs) are an increasingly important class of porous materials that are comprised of organicl igands coordinated to metal-ion clusters. [36][37][38] MOFs can be synthesized to have moderate to high surface areas and can be assembled from molecular building blocks (MBB) with desired/tunable chemical functionality. [36][37][38] MOFs can be synthesized to have moderate to high surface areas and can be assembled from molecular building blocks (MBB) with desired/tunable chemical functionality.

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“…[1][2][3][4][5][6] They have promising potential for av ariety of applications,i ncluding gas storage, [7][8][9][10][11][12][13] gas separations, [14][15][16][17][18][19][20] catalysis, [21][22][23][24][25] sensing, [26][27][28] drug delivery, [29][30][31] magnetism, [32,33] electrical conductivity, [34,35] and nonlinearo ptics. [36][37][38] MOFs can be synthesized to have moderate to high surface areas and can be assembled from molecular building blocks (MBB) with desired/tunable chemical functionality. [9,39] The building block approacha llows for the possibility to create av ast number of MOF structures.…”