Assembly of a two-dimensional oxalate-bridged heterometallic Co(II)(3)Cr(III)(2) coordination polymer

Reaction of CoCl(2).4H(2)O with Ag(3)[Cr(ox)(3)] (3 : 2 mol/mol) in methanol gives rise to an oxalate-bridged complex [Co(MeOH)(2)](3)[Cr(ox)(3)](2).6MeOH that consists of a rare cloverleaf-like layered structure (12,3-net). Ferromagnetic coupling is operative between the adjacent metal ions through the oxalate bridges.     

Lanthanide(III)-cobalt(II) heterometallic coordination polymers with radical adsorption properties

Two new coordination polymers {[Ln(2)(PDA)(6)Co(3)(H(2)O)(6)] x xH(2)O}(n) [Ln = Nd, x = 7 (1); Ln = Gd, x = 3.25 (2); H(2)PDA = pyridine-2,6-dicarboxylic acid] have been prepared under hydrothermal conditions with Ln(NO(3))(3) x 6H(2)O, CoO, and H(2)PDA in a molar ratio of 2:3:6. X-ray crystallographic analyses reveal that they crystallize in the hexagonal group P6/mcc and exhibit a nanotubular 3D framework. The adsorption experiment shows that 1 and 2 can adsorb radicals, which is proven by electron paramagnetic resonance spectra with the characteristic bands of the radicals at g = 2.006 and 2.005, respectively.     

Synthesis and structural characterization of 2-D layered copper(II) styrylphosphonate coordination polymers

We report the synthesis, physicochemical characterization, and crystal structure of Cu-SP (SP?=?styrylphosphonic acid, H₂O₃PCH=CH₂(C₆H₅)), the first reported example of a metal derivative of SP. The starting SP acid was fully characterized by X-ray single-crystal diffractometry, elemental analysis (C and H), ³¹P-NMR, ¹³C-NMR, ¹H-NMR, HPLC, UV–vis, MS, TG, and FT-IR spectroscopy. The copper(II) derivative was synthesized and characterized by DTA-TG and FT-IR, and also its structure was determined from powder data. The crystal structure was refined by the Rietveld method. The crystal structure of Cu-SP shows a layered 2-D architecture, where the organic moieties are pointed toward the interlamellar space. The inorganic layers are composed of Cu²⁺ dimers, where the coordination geometry of Cu²⁺ can be described as distorted trigonal bipyramid. The three coplanar oxygens (O2, O3, and O3) have bond distances of 2.165(9), 1.982(9), and 2.103(11)?Å, respectively. The bond lengths for the apical oxygens (O1 and O2) are 1.908(13) and 1.996(11)?Å, respectively.     

Helical coordination polymers and cyclic dimers formed from heteroleptic thioether-dipyrrinato copper(II) complexes

Heteroleptic copper complexes containing an acetylacetonato ligand and a thioether derivatized dipyrrinato ligand are shown to form oligomers and polymers in the solid state.     

Water-induced reversible dissolution/reorganization transformations of Cu(Ⅱ)-K(I) heterometallic coordination polymers

Three new heterometallic coordination compounds, namely, [KCu(I3)(L)2(H2O)2]n(1), [KCu(I3)(L)2(H2O)]n(2) and [CuK4(I3)2(L′)4]n(3), were prepared and characterized(HL=5-methylpyrazine-2-carboxylic acid, HL′=p-tolylacetic acid). Structural studies revealed that 1 and 2 exhibit 3D frameworks with rectangular channels occupied by triiodide ions. Both compounds can be symbolized as a 5-connected net with pcu topology. In compound 3, a one-dimensional polyhedral chain is connected by hexanuclear mask like clusters [Cu2K4O8]. These chains are further linked each other via rare(1,1,3,3)-triiodide ion-bridging units to generate a 3D(4,5,6)-connected net with the point symbol of {12}2{4·122}4{46}{48·62}4{49·66}4. It is noteworthy that water-induced reversible dissolution/reorganization processes occur between 1/2 and [Cu(L)2(H2O)]n·3nH2O. The thermal and photoluminescence properties of compounds 1, 2, and 3 were investigated as well.     

Chelating or bridging Pd(II) and Pt(II) metalloligands from the functional phosphine ligand N-(diphenylphosphino)-1,3,4-thiadiazol-2-amine. New heterometallic Pd(II)/Pt(II) and Pt(II)/Au(I) complexes

The reaction of two equivalents of the functional phosphine ligand N-(diphenylphosphino)-1,3,4-thiadiazol-2-amine Ph2PNHC=NNCHS (2) with [PdCl2(NCPh)2] in the presence of NEt3 gives the neutral, P,N-chelated complex cis-[Pd(Ph2PN=CNN=CHS)2] ([Pd(2-H)2], 3b), which is analogous to the Pt(II) analogue cis-[Pt (Ph2PN=CNN=CHS)2] ([Pt(2-H)2], 3a) reported previously. These complexes function as chelating metalloligands when further coordinated to a metal through each of the CH-N atoms. In the resulting complexes, each endo-cyclic N donor of the thiadiazole rings is bonded to a different metal centre. Thus, the heterodinuclear palladium/platinum complexes cis-[Pt(Ph2PN=CNN=CHS)2PdCl2]([Pt(2-H)2·PdCl2], 4a) and cis-[Pd(Ph2PN=CNN=CHS)2PtCl2]([Pd(2-H)2·PtCl2], 4b) were obtained by reaction with [PdCl2(NCPh)2] and [PtCl2(NCPh)2], respectively. In contrast, reaction of 3a with [AuCl(tht)] occurred instead at the P-bound N atom, and afforded the platinum/digold complex cis-[Pt{Ph2PN(AuCl)=CNN=CHS}2] ([Pt(2-H)2(AuCl)2], 5). For comparison, reaction of 4a with HBF4 yielded cis-[Pt(Ph2PNH=CNN=CHS)2PdCl2](BF4)2([H24a](BF4)2, 6), in which the chelated PdCl2 moiety is retained. Complexes 3b, 4a·CH2Cl2, 4b·0.5C7H8, 5·4CHCl3 and 6 have been structurally characterized by X-ray diffraction.     

Cluster-based copper(II) coordination polymers with azido bridges and chiral magnets

Three homochiral layered complexes, [Cu3(R-chea)2(N3)6]n (1), [Cu3(S-chea)2(N3)6]n (2) (chea = 1-cyclohexylethylamine) and [Cu3(S-phpa)2(N3)6]n (3) (phpa = 1-phenylpropylamine), and three novel cluster-based coordination polymers, [Cu6(1,2-pn)4(N3)12]n (4) (1,2-pn = 1,2-diaminopropane), [[Cu8(en)4(N3)16] x H2O]n (5) (en = ethylenediamine) and [Cu6(N-Ipren)2(N3)12]n (6) (N-Ipren = N-isopropylethylenediamine), have been synthesized by the self-assembly reactions of Cu(NO3)2 x 3H2O, NaN3 and small organic amine ligands. Their crystal structures are determined by single-crystal X-ray diffraction. Complexes are composed of neutral 2D brick wall networks with only end-on azido bridges. Complexes and are 3D coordination polymers featuring copper-azido clusters and [Cu(diamine)2]2+ units which are linked by the azido bridges. Complex is a 3D coordination framework based on the hexanuclear copper(II) clusters [Cu6(N3)12(N-Ipren)2]. Magnetic studies show that complexes are interesting chiral ferromagnets with the magnetic transition temperature at ca. 5.0 K. Complexes and show ferromagnetic coupling in the copper-azido cluster units and antiferromagnetic interaction between neighboring units, while complex shows ferromagnetic ordering at 3.2 K.     

2]Catenanes and inclusion complexes derived from self-assembled rectangular Pd(II) and Pt(II) metallocycles

New inclusion complexes and [2]catenanes were self-assembled from a fluorescent diazapyrenium based ligand, a Pd(II) or Pt(II) complex, and cyclic or acyclic electron rich aromatic guests in aqueous and organic media. The molecular rectangles display a π-deficient cavity suitable to incorporate π-donor aromatic systems. The inclusion complexes between the metallocycles and phenylenic () and naphthalenic () derivatives were studied by NMR, UV-vis and fluorescence spectroscopy. The crystal structure of () ? ·6PF(6) confirmed the insertion of the guest into the cavity of the metallocycle. Following the same self-assembly strategy, the use of polyethers , as π-donors resulted in the self-assembly of the [2]catenanes (,)·6PF(6). Single-crystal X-ray analysis of ()·6PF(6) revealed the [2]catenane structure being stabilized by π-stacking and [C-HO] interactions.     

Phosphorescent self-assembled Pt(II) tetranuclear metallocycles

A series of rigid Pt(II) diimine diacetylide complexes and their corresponding metallocyclic derivatives were synthesized through coordination-driven self-assembly. The photophysical properties of these complexes have been studied in detail, revealing exceptionally high RT phosphorescence quantum yields and lifetimes when the excited state becomes localized on the π-conjugated bridging-ligand following intramolecular charge-transfer sensitization.     

Rare configuration of tautomeric benzimidazolecarboxylate ligands in cadmium(II) and copper(II) coordination polymers

Two Cd(HBimc)-based isomers, [Cd(HBimc^N)(HBimc^T)(H₂O)]·3.5H₂O·EtOH (1a·3.5H₂O·EtOH, H₂Bimc=1H-benzimidazole-5-carboxylic acid) and [Cd(HBimc^N)(HBimc^T)(H₂O)] (1b), and two Cu(HMBimc)-based coordination polymers, [Cu(HMBimc^N)₂(H₂O)]·1/2H₂O (2·1/2H₂O, H₂MBimc=2-methyl-1H-benzimidazole-5-carboxylic acid) and [Cu(HMBimc^T)₂]·2THF·H₂O (3·2THF·H₂O), were self-assembled from Cd(ClO₄)₂·6H₂O/H₂Bimc and Cu(ClO₄)₂·6H₂O/H₂MBimc systems, respectively. Compound 1a adopts a ladder-like chain structure, comprised of a hydrogen-bond-stabilized Cd₂(HBimc^N)₂-metallocyclic stair and a 1D straight -(Cd-HBimc^T)_n- edge, whereas compound 1b exhibits a 2D (4,4)-rhombus layered structure, intercrossed by 1D -(Cd-HBimc^N)_n- chains and -(Cd-HBimc^T)_n- chains. Compound 2 shows a 1D double-stranded wave-like chain from two single-stranded wave-like -(Cu-HMBimc^N)_n- chains and compound 3 adopts a 2D (4,4)-topological layer structure, intercrossed by subunits of 1D -(Cu-HMBimc^T)_n- chains. Interestingly, a pair of tautomeric HBimc building blocks—normal (N or HBimc^N) and tautomer (T or HBimc^T)—is simultaneously included in the structures of 1a and 1b, whilst the N- and T-configured HMBimc building blocks are present as separate entities in Cu species, 2 and 3, respectively. The existence of only a tautomer (T) mode of the benzimidazolecarboxylate-based ligand in a Cu(II) network is observed for the first time.