Low dimensional antiferromagnetic materials have received considerable attention from both chemists and physicists because of their potential application as functional materials, such as superconductors. Magnetic moments can propagate via multiple pathways such as via two-halide superexchange interactions in A₂MX₄ systems (where A is an organic cation and X is halides), or through bonding conjugated systems.

One route for generating two-halide A₂MX₄ systems is via crystal packing of transition metal anions and organic cations. Following this method, we have prepared a series compounds in the (5-SAP)₂CuX ₄ family (where 5-SAP is a 5-substituted-2-aminopyridinium cation) and the A₂CuX₄ family. Eleven compounds have been prepared. They include bis(2-amino-5-fluoropyridinium) tetrachlorocuprate(II) (5-FAP) ₂CuCl₄ (1), bis(2-amino-5-fluoropyridinium) tetrabromocuprate(II) (5-FAP)₂CuBr₄ (2), bis(2-amino-5-iodopyridine) dibromocopper(II) (5-iap)₂CuBr ₂ dimer (3) and chain (4) forms, bis(2-amino-5-iodopyridine) dichlorocopper(II) hydrate (5-iap)₂CuCl₂·1.7H ₂O (5), 2-amino-5-ammoniumpyridinium trichlorocuprate(II) chloride (DAP)(CuCl₃)Cl (6), bis(2-amino-3-chloro-5-trifluoromethylpyridinium) tetrabromocuprate(II) (TMCAP)₂CuBr₄ (7) and its tetrachlorocuprate(II) analog (TMCAP)₂CuCl₄ (8), bis(4-aminopyridinium) tetrabromocuprate(II) monohydrate (4-AP) ₂CuBr₄-H₂O (9), bis(3-methylpyridinium) tetrabromocuprate(II) (3-MP)₂CuBr₄ (10) and bis[methyl(2-phenylethyl)ammonium] tetrabromocuprate(II) (NMPH)₂ CuBr₄ (11). The structures and magnetic properties have been studied. Experimental data and theoretical calculations show that the strength of magnetic exchange is related to the geometric parameters of the non-bonding two-halide contacts, rather than direct contact between the copper(II) ions.

The self-assembly technique can also be used to prepare magnetic networks. A variety of coordination polymers with magnetic properties have been synthesized based on different N-heterocyclic ligands such as pyrazine and its derivatives. Magnetic exchange can propagate through the conjugated system. As an extension of this method, we focused on using some new polyamines including 1,2,4,5-tetrazine (tetz), 1,2,4-triazine (tz) and the amino derivative 3-amino-1,2,4-triazine (atz) as ligands. Four new complexes have been prepared. They include bis(hexafluoroacetylacetonato)copper(II) Cu(hfac)₂(C₂H₂N₄) (13), bis(hexafluoroacetylacetonato)triazinecopper(II) Cu(hfac)₂(tz) (15), bis(hexafluoroacetylacetonato)(3-aminotriazine)copper(II) Cu(hfac) ₂(atz)₂ (16) and hexakis(hexafluoroacetylacetonato)bis(3-aminotriazine)tricopper(II) Cu₃(hfac)₆(atz)₂ (17). The crystal structures and magnetic properties have been studied. The magnetic data show they are paramagnetic materials because of the weak coordination bonds. To compare with its atz analog, 2-aminopyrazine (apz) was also used and three new complexes have been prepared. They include hexakis(hexafluoroacetylacetonato) bis(2-amino-pyrazine)tricopper(II) Cu₃(hfac)₆ (apz)₂ (18), bis(hexafluoroacetylacetonato)aminopyrazinecopper(II) Cu(hfac)₂(apz)₂ (19) and bis(acetylacetonato)aminopyrazinecopper(II) Cu(acac)₂(apz)₂ (20). The structures and their magnetic properties have been investigated.