Zwitterionic Dicarboxylate Ligand Research Articles

Electrocatalytic properties of three new POMs-based inorganic–organic frameworks with flexible zwitterionic dicarboxylate ligands

Three POMs–based inorganic–organic frameworks, namely, [Cu2(L)2(SiW12O40)(H2O)2]·6H2O (1), [Co2(L)2(SiW12O40)(H2O)8]·8H2O (2) and [Ni2(L)2(SiW12O40)(H2O)8]·6H2O (3), (L=1,1′-(1,4-phenylene-bis(methylene))-bis(pyridine-3-carboxylic acid)), have been synthesized and characterized by elemental analyses, IR, XRPD, TG, and single crystal X-ray diffraction. Compound 1 contains 1D double chains decorated by {Cu2(L)4(H2O)2} units and the 1D chains and POMs are stacked to yield 2D frameworks. Compound 2 displays a 2D network constructed from 1D zigzag chains and POMs arranged in ABAB mode. Compound 3 consists of big square girds and the POMs are dispersed in the middle of the two adjacent girds, forming 2D networks. Compounds 1–3 all show structural integrity in aqueous solutions at different pH values and in common organic solvents. Additionally, the fluorescence and electrochemical properties of compounds 1–3 are also investigated. Compounds 1–3 exhibit good electrocatalytic activities for the reduction of NaNO2 and H2O2.

Three New Complexes Based on the Flexible Zwitterionic Dicarboxylate Ligand: Synthesis, Structures, and Properties

AbstractThree new complexes have been prepared based on the transition metals and zwitterionic dicarboxylate ligand 1,1′‐(1,4‐phenylene‐bis(methylene))‐bis(pyridine‐3‐carboxylic acid) (L), whose formulas are {[Cd4(L)(SO4)]· (Cl)6}n (1), [Zn(L)Cl2]n (2), and [Co(L)Cl2]n (3), respectively. Complexes 1–3 have been characterized by elemental analyses, IR spectroscopy, XRD, thermal analyses and single crystal X‐ray (powder) diffraction. 1 crystallizes in monoclinic space group C2/m, displaying a 2‐D layer structure with three unique Cd2+ centers. 2 and 3 are isomorphic structures with the orthorhombic Cmca space group. They exhibit a 1‐D zigzag chain, which can be linked to generate a 2‐D layer via hydrogen bonding interactions (CH···O). Moreover, electrochemical behavior reveals that the redox reaction of 3‐CPE is a surface‐controlled reaction. And the luminescent properties of the title complexes have been investigated at room temperature.

Two new carboxylate–oxygen bridged trinuclear M(II) (M[dbnd]Mn and Co) compounds with zwitterionic dicarboxylate ligands: crystal structures and magnetism

Two new Mn(II) and Co(II) coordination polymers with azide and zwitterionic dicarboxylate ligands L1 and L2 (L1=[4-((1-carboxylatobenzyl)pyridimium-3-yl) benzoic acid] chloride, L2=[1,1′-bis(4-carboxylatobenzyl)-4,4′-bipyridinium] dichloride) were synthesized and structurally and magnetically characterized. They are formulated as [Mn3(L1)4(N3)(CH3CH2OH)(H2O)]ClO4·4H2O (1) and [Co3(L2)4(N3)2(H2O)2]·4NO3 (2). Compound 1 contains two different linear trinuclear [Mn3(COO)8(CH3CH2OH)2]2− and [Mn3(COO)6(H2O)2(N3)2]2− units built from the mixed bridges of (μ-COO)2(μ2-Ocarboxylate). The trinuclear units are alternately linked into 1D chains by L1. Compound 2 contains linear trinuclear [Co3(N3)2(COO)4(H2O)2] units built from the mixed bridges (μ-COO)2(μ-H2O). Magnetic studies demonstrated that the mixed triple bridges are antiferromagnetic in compounds 1 and 2.

Crystal structures and magnetic properties of three new azide-bridged dinuclear metal(II) compounds with zwitterionic dicarboxylate ligand

Three coordination polymers of different transition metal ions with azide and the zwitterionic dicarboxylate ligand 1-carboxymethylpyridinio-3-benzoate (L) were synthesized, and structurally and magnetically characterized. They are formulated as [M(L)(N3)·2H2O] (M=Co, 1; Mn, 2) and [Cu(L)(N3)·H2O] (3). In the isomorphous compounds 1 and 2, octahedrally coordinated metal ions are linked by the (μ-EO-N3)2 (EO=end-on) double bridges to give dinuclear motifs, which are linked by the zwitterionic dicarboxylate ligands to produce one-dimensional (1D) coordination chains. Compounds 3 and 1 (and 2) are pseudo-isomorphous, since they crystallize in the same space group, exhibit similar crystal structures, but have different numbers of coordinated water molecules. The chains are further stabilized and packed into 3D architectures through intra- and interchain hydrogen bonding and/or π–π stacking interactions. Magnetic studies on 1 and 3 reveal that the (μ-EO-N3)2 double bridges mediate ferromagnetic coupling between metal(II) ions.

Magnetic coupling and slow relaxation of magnetization in chain-based Mn(II), Co(II), and Ni(II) coordination frameworks.

Three isomorphous coordination polymers based on the chain with triple (μ-1,1-N3)(μ-1,3-COO)2 bridges have been synthesized from a new zwitterionic dicarboxylate ligand [L(-) = 1-(4-carboxylatobenzyl)pyridinium-4-carboxylate]. They are of formula [M(L)(N3)]n·3nH2O [M = Mn(II), Co(II), and Ni(II)]. In these compounds, the mixed-bridge chains are linked into 2D coordination networks by the N-benzylpyridinium spacers. The magnetic properties depend strongly on the nature of the metal center. The magnetic coupling through (μ-1,1-N3)(μ-1,3-COO)2 is antiferromagnetic in the Mn(II) compound but ferromagnetic in the Co(II) and Ni(II) analogues. Magnetostructural analyses indicate that the magnitude of the magnetic coupling can be correlated to the M-N-M angle of the azide bridge and the average M-O-C-O torsion angle of the carboxylate bridge. As the values of these parameters increase, the antiferromagnetic coupling for Mn(II) decreases while the ferromagnetic coupling for Co(II) increases. With strong magnetic anisotropy, the Co(II) compound behaves as a single-chain magnet showing hysteresis and Glauber-type slow dynamics probably in the infinite-chain region, with Δ(τ)/k = 86 K, Δ(ξ)/k = 26 K, and Δ(A)/k = 34 K. With weaker anisotropy, the Ni(II) species shows slow relaxation of magnetization at much lower temperature.

Synthesis, structure and magnetic properties of manganese(II) coordination polymer with azido and zwitterionic dicarboxylate ligand

Abstract A coordination polymer formulated as {[Mn2L(N3)4]·2H2O}n(1) [L = 1,4-bis(pyridinil-3-carboxylato)-l,4-dimethylbenzene] was synthesized and structurally and magnetically characterized. The uniform Mn(II) chains with mixed (μ-EO-N3)2(μ-COO) triple bridges (EO = end-on) are linked by L ligands to generate a 2-fold interpenetrating 3D framework. Meanwhile, magnetism analysis reveals antiferromagnetic coupling for 1.

Structures and magnetic properties of copper(ii) and manganese(ii) polymers derived from pseudohalides and a flexible zwitterionic dicarboxylate ligand

The flexible zwitterionic dicarboxylate ligand 1,4-bis(4-carboxylato-1-pyridinium)butane (bcpb) assumes different conformations to collaborate with pseudohalides in various coordination modes to produce coordination polymers in which distinct anionic motifs with mixed carboxylate and pseudohalide bridges are interlinked by the cationic butylenebis(pyridinium) tethers. The Cu(II) compound, [Cu2(bcpb)(N3)4]n·nH2O (1), is a 1D coordination polymer based on the defective dicubane-like [Cu4(μ3-1,1,1-N3)2(μ-1,1-N3)2(μ-1,1-OCO)2] cluster. With Mn(II), four distinct 3D coordination polymers, [Mn4(bcpb)4(N3)(H2O)4]n(ClO4)7n·nCH3OH·3nH2O (2), [Mn2.5(bcpb)(N3)5(H2O)2]n (3), [Mn2(bcpb)(N3)4]n·nH2O (4), and [Mn2(bcpb)(NCO)4]n·nH2O (5), were characterized. 2 is the first Mn(II) compound with the rare μ4-1,1,3,3 azide bridge and exhibits an unusual 3D framework based on the [Mn4(μ4-1,1,3,3-N3)(μ-1,3-OCO)6] cluster. In 3, the unique undulated honeycomb-like [Mn2(μ-1,3-N3)3]n layers are interlinked into a 3D framework by disordered [Mn(μ-1,1-N3)4(μ-1,3-OCO)2] and [(O(aqua)-H)2···OCO]2 moieties, and the bcpb ligands serve as additional interlayer linkers to lead to the rare self-catenated 6(6) net. 4 and 5 show 3-fold interpenetrated 3D frameworks based on the chains with (μ-1,1-N3)2(μ-1,3-OCO) and (μ-N,N-NCO)2(μ-1,3-OCO) bridges, respectively. Magnetic studies indicated that 1 shows competing ferromagnetic and antiferromagnetic interactions. Compounds 2-5 all show antiferromagnetic coupling between Mn(ii) ions, while 3 shows 3D ordering. Analyses of magneto-structural data suggest a general trend that the antiferromagnetic interaction through (μ-1,1-N3)2(μ-1,3-OCO) or (μ-N,N-NCO)2(μ-1,3-OCO) increases with a decrease of the Mn···Mn distance.

Ferromagnetic interactions through double hydrogen bonding bridges in manganese(ii) coordination polymers

Three isostructural Mn(II) compounds with a zwitterionic dicarboxylate ligand and different pseudohalides were synthesized, and then structurally and magnetically characterized. They are formulated as [Mn(L)(X)(2)(H(2)O)(2)](n) [X = N(3)(-) (1), NCO(-) (2), NCS(-) (3), L = 1,4-bis(4-carboxylato-1-pyridinium)butane]. In these compounds, adjacent Mn(II) ions are connected into coordination chains by long zwitterionic linkers and into hydrogen-bonded chains by short double O-H···N bridges involving coordinated water and pseudohalide ligands. Magnetic studies revealed for the first time that the double hydrogen bridges induce ferromagnetic coupling between the Mn(II) ions.

Structures and magnetism of metal(II) compounds with mixed azide and carboxylate bridges derived from zwitterionic dicarboxylate ligands

Three coordination polymers of different transition metal ions with azide and flexible zwitterionic dicarboxylate ligand 1-carboxymethylpyridinium-4-benzoate (L) were synthesized and structurally and magnetically characterized. They are formulated as [M(L)(N3)]·H2O (M=Co, 1 and Ni, 2) and [Cu3(L)2(N3)4]·7H2O (3). In the isomorphous compounds 1 and 2, neighboring metal ions are linked by mixed triple (μ-EO-N3)(μ-COO)2 bridges to give an anionic chain of [M(N3)(COO)2]n, and each chain is cross-linked by the cationic 1-methylpyridinium-4-phenyl spacers to give a two-dimensional coordination layer. Magnetic studies demonstrated that the triple bridge transmits intrachain ferromagnetic interactions but show different bulk properties: compound 1 diplays a new SCM-based material exhibiting antiferromagnetic ordering, metamagnetic transition, and field-modulated slow dynamics, while compound 2 shows the usual one-dimensional ferromagnetism. Compound 3 consists of three-dimensional coordination framework in which Cu(II) chains with alternating double (μ-EO-N3)2 bridges and triple (μ-EO-N3)(μ-COO)(μ-Ocarboxylate) bridges are interlinked by the organic spacer. Magnetic studies suggested that ferromagnetic interactions between the neighboring Cu(II) ions through the alternating bridges.

Mixed azide and carboxylate bridged trinuclear Mn(ii) and Co(ii) motifs in coordination ladders: structures and magnetism

Two isomorphous Mn(II) and Co(II) coordination polymers with an azide and zwitterionic dicarboxylate ligand as coligands were synthesized and structurally characterized, and their magnetic properties were studied. They are formulated as [M3(L)2(N3)6(H2O)2]·2H2O (M = Mn (1), Co (2), L = 1,2-bis(4-carboxylatopyridinium-1-methylene)benzene). The compounds contain anionic linear [Mn3(N3)6(COO)4(H2O)2]4− units built from the simultaneous bridges of a syn–syn carboxylate and two end-on azides. The anionic trinuclear units are linked into ladder-like coordination polymers by the cationic bis(pyridinium) tether of the organic ligand. Analyses of the temperature- and field-dependent magnetic data of the compounds revealed that the mixed [(COO)(EO–N3)2] triple bridges transmit antiferromagnetic and ferromagnetic coupling in 1 and 2, respectively.

Two novel 2D cadmium(ii) MOFs based on flexible bis(imidazolyl) and zwitterionic dicarboxylate ligands

The reaction of 1,4-bis((pyridinium-4-carboxylic acid)methyl)benzene dibromide (Bpmb-2HBr), Cd(NO3)2·4H2O with 1,2-bis(imidazol-1′-yl)ethane (Bime) and 1,4-bis(imidazol-1′-yl)butane (Bimb) gave rise to two novel 2D Cd(II) coordination polymers, [Cd1.5(Bime)(Bpmb)0.5(μ-Br)Br2·DMF]n (1) and [Cd2(Bimb)2(μ-Br)2Br2]n (2), respectively, in which coordination of μ-Br− and monodentate Br− with Cd(II) generates an unprecedented trimeric [Cd3(μ-Br)2Br4] unit in 1 and a dimeric [Cd2(μ-Br)2Br2] unit in 2. In 1, gauche-Bime links the central six-coordinated Cd(II) of the trimers into a 1D double chain, anti-Bpmb further bridges the terminal four-coordinated Cd(II) of the trimers in the opposite direction to generate a 2D layer. Complex 2 is a 2D corrugated layer consisting of perpendicular left- and right-handed helical chains constructed through anti-anti-gauche-conformated Bimb bridging the neighboring six-coordinated Cd(II) of [Cd2(μ-Br)2Br2] units. The thermal stability and fluorescent properties of the two complexes have also been studied.

Experimental and Theoretical Studies on the Magnetic Properties of Manganese(II) Compounds with Mixed Isocyanate and Carboxylate Bridges

Two manganese(II) isocyanate complexes with different flexible zwitterionic dicarboxylate ligands, [Mn(2)(bcpp)(NCO)(4)](n) (1; bcpp=1,3-bis(N-carboxylatomethyl-4-pyridinio)propane) and [Mn(2)(bcp)(NCO)(4)](n) (2; bcp=bis(N-carboxylatomethyl)-4,4'-bipyridinium, have been synthesized and characterized by X-ray crystallography and magnetic measurements. Both compounds consist of two-dimensional coordination layers in which uniform anionic chains with mixed (NCO)(2)(COO) triple bridges are cross-linked by flexible cationic 4,4'-trimethylenedipyridinium spacers. Magnetic studies revealed antiferromagnetic interactions through the triple bridges (J=-8.0 cm(-1) (1) and J=-8.6 cm(-1) (2)), which are stronger than those in the isoelectronic analogue (N(3))(2)(COO). To complement the experimental data, periodic and finite-cluster DFT and CASPT2 calculations were performed on the dimeric units of the (NCO)(2)(COO) and (N(3))(2)(COO) mixed-bridged systems to support the Heisenberg picture and stress the relative efficiency of the magnetic couplers. It was found that the isocyanate ligand plays a greater role in the conveyance of antiferromagnetic behavior than the azide counterpart, and that both pseudohalide bridges function cooperatively with the carboxylate group.

Metal–organic supramolecular architectures derived from a new zwitterionic dicarboxylate ligand

A series of new coordination compounds with 1-carboxymethylpyridinium-4-benzoate (L) and transition metal ions have been synthesized. They are formulated as [M(L)2(H2O)4] · 4H2O M=Mn (1) and Co (2), {[M(L)2] · xH2O} n M=Mn, x = 1 (3); M=Co, x = 2 (4), and M=Cu, x = 3 (5). In 1 and 2, the zwitterionic dicarboxylate ligand is monodentate through only one carboxylate to generate mononuclear molecules. The molecules are assembled through O–H ··· O interactions to give 3-D pillared layer-like architectures, in which interesting 1-D tape-like hydrogen bonding motifs are connected into 2-D layers via carboxylate-mediated hydrogen bonds. In 3–5, the organic ligands serve as bridges with one carboxylate monodentate and the other chelating, and the metal ions are linked by double bridges to give 1-D polymeric chains, which are zigzag (3) or stair-like (4 and 5) due to the cis or trans coordination geometry around metal ions. The chains are further stabilized and associated into 3-D architectures through intra- and interchain hydrogen bonding and/or π–π stacking interactions.

Diverse Manganese(II) Coordination Polymers with Mixed Azide and Zwitterionic Dicarboxylate Ligands: Structure and Magnetic Properties

The reactions of manganese(II) acetate or perchlorate, sodium azide, and the inner-salt-type dicarboxylate ligand 1,3-bis(4-carboxylato-1-pyridinium)propane (L) under different conditions yielded four different Mn(II) coordination polymers with mixed azide and carboxylate bridges: {[Mn(L)(N(3))]ClO(4).0.5H(2)O}(n) (1), {[Mn(2)(L)(2)(N(3))(2)][Mn(N(3))(4)(H(2)O)(2)].2H(2)O}(n) (2), {[Mn(2)(L)(2)(N(3))(2)(H(2)O)(2)]Br(N(3)).2H(2)O}(n) (3), and [Mn(4) (L)(2)(N(3))(8)](n) (4). The compounds exhibit great diversity in their structures and magnetic properties. Both 1 and 2 contain anionic chains featuring a mixed (OCO)(2)(EO-N(3)) triple bridge (EO = end-on) between adjacent Mn(II) ions. In 1, two independent sets of triple bridges with apparently different structural parameters alternate in the AABB sequence, and the resulting alternating chains are cross-linked into a cationic 3D framework by the cationic dipyridinium spacers. Differently, the chains in 2 have uniform bridges and are interlinked into a 2D coordination layer. An expression of the magnetic susceptibility for 1D systems with alternating J(1)J(1)J(2)J(2) interactions has been deduced and applied to 1. Magnetic studies on 1 and 2 reveal that the (OCO)(2)(EO-N(3)) triple bridges induce antiferromagnetic coupling between Mn(II) ions, and magnetostructural analyses suggest that the magnitude of the coupling can be correlated to the Mn-N and Mn-N-Mn parameters. Compound 3 contains 2D coordination layers in which the chains with alternating double EO-azide and double carboxylate bridges are interlinked by the dipyridinium spacers, and magnetic studies suggest alternating ferro- and antiferromagnetic interactions through the alternating bridges. The 3D framework of compound 4 is formed by the organic ligands interlinking the unique manganese-azide-carboxylate layers in which the [Mn(4)(mu(3)-N(3))(2)(mu(2)-N(3))(2)(mu(2)-COO)(4)] clusters are interlinked through EE-azide bridges (EE = end-to-end). The structure represents a novel type of self-catenated 8-connected 3D net. Magnetostructural analyses suggest that all of the short bridging moieties in 4, including (mu(3)-EO-N(3))(2), (OCO)(EO-N(3)), (OCO)(EO-N(3))(2), and single EE-N(3), propagate antiferromagnetic coupling.

Structures and magnetism of azide- and carboxylate-bridged metal(ii) systems derived from 1,2-bis(N-carboxymethyl-4-pyridinio)ethane

Four coordination polymers of different transition metal ions with azide and the zwitterionic dicarboxylate ligand 1,2-bis(N-carboxymethyl-4-pyridinio)ethane (bcpe) were synthesized, and structurally and magnetically characterized. They are formulated as [M(2)(bcpe)(N(3))(4)].H(2)O (M = Mn, 1; Co, 2; and Ni, 3) and [Cu(3)(bcpe)(N(3))(6)].(H(2)O)(2) (4). In the isomorphous compounds , octahedral metal ions are linked by the mixed (micro(2)-syn,syn-COO)(mu(2)-EO-N(3))(2) triple bridges (EO = end-on) to give anionic uniform chains, which are cross-linked by the cationic bis(pyridinium) spacers to produce two-dimensional coordination layers. Magnetic studies demonstrated that the magnetic coupling through the mixed triple bridge is antiferromagnetic in the Mn(ii) compound (1) but ferromagnetic in the Co(ii) and Ni(ii) species (2 and 3). Compound 4 also consists of two-dimensional coordination layers in which Cu(ii) chains are interlinked by the organic spacers, but the chain has mixed mu(2)-EO-azide, mu(3)-EO-azide and mu(2)-O(carboxylate) bridges and features tetranuclear dicubane-based units sharing Cu ions or alternatively linear trinuclear units connected by long axial Cu-N/O bonds. Magnetic studies suggested that the Cu(ii) ions linked by the double azide bridges in the equatorial-equatorial fashion are strongly coupled to give a ferromagnetic S = 3/2 ground state for the trinuclear units, with very weak antiferromagnetic interactions through the equatorial-axial bridges between the units.

Mixed azide–carboxylate bridged tri- and tetranuclear MnII clusters in coordination polymers derived from a zwitterionic dicarboxylate ligand: structures and magnetism

Two Mn(II) coordination polymers with azide and the zwitterionic dicarboxylate ligand bis(N-carboxymethyl-4-pyridinium) (bcp) were synthesized, and structurally and magnetically characterized. They are formulated as [Mn(3)(bcp)(2)(N(3))(2)(SO(4))(2)(H(2)O)(4)].6H(2)O (1) and [Mn(4)(bcp)(2)(N(3))(8)(H(2)O)(2)].4H(2)O (2). Compound 1 contains anionic linear [Mn(3)(N(3))(2)(COO)(4)(SO(4))(2)(H(2)O)(4)](4-) units with simultaneous mu(2)-EO (end-on) azide, sulfate and carboxylate bridges, while compound 2 contains [Mn(4)(COO)(4)(N(3))(8)(H(2)O)(2)](4-) clusters with mixed mu(2)-EO azide, mu(3)-EO azide and carboxylate bridges. In these compounds, the anionic tri- or tetranuclear units are linked into coordination chains by the cationic bipyridinium spacers, and are also hydrogen bonded into chains by double O-H...O bridges. Magnetic analyses were carried out on temperature-variable susceptibility data for both compounds, and also on isothermal magnetization data for 1. It is revealed that all the mixed double and triple bridges, [(EO-N(3))(COO)(SO(4))] in 1, [(COO)(EO-N(3))(2)] and [(COO)(EO-N(3))] in 2, transmit antiferromagnetic coupling between Mn(II) ions. The [(EO-N(3))(2)] bridge in , with Mn-N-Mn = 96.6 degrees, also transmits antiferromagnetic coupling, providing the first example in the antiferromagnetic regime predicted theoretically for double EO-azide bridges between Mn(II) ions. The double hydrogen bonding [(O-H...O)(2)] bridges in both compounds induce weak antiferromagnetic interactions.

Supramolecular architectures through first- and second-sphere coordination of a flexible zwitterionic dicarboxylate ligand

The supramolecular architectures formed through the first- or second-sphere coordination between 1,4-diazoniabicyclo[2.2.2]octane-l,4-diacetate and different divalent metal ions have been described. They are formulated as [Ni(SCN) 2(H 2O) 4](L) 2(H 2O) 2 ( 1), [M(SCN) 2(H 2O) 8](L) 2(H 2O) 4 M = Co ( 2) and Mn ( 3) and [Zn(L)(SCN) 2] ( 4). In the Zn(II) compound, the zwitterionic ligand is directly coordinated to the metal ion, and the tetrahedral coordination of Zn(II) and the C-shaped bridging conformation of the ligand combine to result in a M 2L 2 metallacyclic molecule. In the Ni(II), Co(II) and Mn(II) compounds, the ligand is not involved in first-sphere coordination, and the crystal structure is governed by the second-sphere coordination (hydrogen bonding involving the first sphere). The octahedral [M(SCN) 2(H 2O) 4] first-sphere coordination provides a specific array of hydrogen donor sites for the pseudo-octahedral second-sphere coordination of six carboxylate groups from different S-shaped zwitterions, and the zwitterions serve as 3-connecting bridges between the first-sphere motifs to produce a hydrogen-bonded rutile-type network. The structures illustrate the great potential of combining the first- or second-sphere coordination to produce intriguing metal–organic networks.

Antiferro- and Ferromagnetic Interactions in Mn(II), Co(II), and Ni(II) Compounds with Mixed Azide−Carboxylate Bridges

A series of transition metal coordination polymers with azide and flexible zwitterionic dicarboxylate ligands was synthesized and structurally and magnetically characterized. These compounds are formulated as [M(2)(L(1))(N(3))(4)] (L(1) = 4,4'-trimethylenedipyridinio-N,N'-diacetate and M = Mn, 1; Co, 2; and Ni, 3) and [ML(2)(N(3))(6)(H(2)O)(2)] (L(2) = 4,4'-dipyridinio-N,N'-diacetate and M = Mn, 4; Co, 5). The isomorphous compounds 1-3 consist of two-dimensional coordination layers in which the anionic uniform chains with mixed triple bridges (two end-on (EO) azides and a syn-syn carboxylate) are cross-linked by the flexible cationic 4,4'-trimethylenedipyridinium spacers, while the isomorphous compounds 4 and 5 consist of alternating chains with triple (two EO azides plus a carboxylate) and double (two end-to-end azides) bridges, the 4,4'-dipyridinium spacers serving as side bridges along the chain. Magnetic studies demonstrated that the triple bridge transmits antiferromagnetic coupling in the Mn(II) compounds (1 and 4) but ferromagnetic coupling in the Co(II) and Ni(II) species (2, 3, and 5). The differences have been discussed in terms of the collaboration or competition between the carboxylate and azide pathways. Compound 4 exhibits alternating antiferromagnetic interactions, while alternating ferromagnetic-ferromagnetic-antiferromagnetic interactions with spin canting are suggested for 5.