Two‐Dimensional Monovalent Copper Halide Coordination Polymers Incorporating Anti‐Conformation 3,3′‐Bipyridine

Hydrothermal treatment of aqueous mixtures of copper(II) halides and 3,3′‐bipyridine (3,3′‐bpy) has afforded the coordination polymers [CuCl(3,3′‐bpy)]_n ( 1 ) and [Cu₂Br₂(3,3′‐bpy)]_n ( 2 ), which were analyzed via single crystal X‐ray diffraction, infrared spectroscopy, and elemental analysis. The structure of 1 consists of two‐dimensional (2‐D) layers constructed from the linkage of castellated one‐dimensional (1‐D) [CuCl]_n stepped chains through anti‐conformation 3,3′‐bpy tethers. Compound 2 presents a related 2‐D sheet motif, albeit built from infinite 1‐D [Cu₂Br₂]_n ladders strutted by 3,3′‐bpy ligands in anti conformation. In both cases neighboring 2‐D sheets stack into 3‐D via weak C–H···halogen interactions.     

Assembly of Chiral Two- and Three-dimensional Copper(I) Pseudohalide Based Coordination Polymers with Asymmetrically Substituted Pyrazine and Pyrimidine Ligands

The coordination polymers [(CuCN)₂(μ-2 Mepyz)], [CuCN(μ-2 Mepyz)] and [CuCN(μ-4 Mepym)] ( 1 – 3 ) (2 Mepyz = 2-methylpyrazine; 4 Mepym = 4-methylpyrimidine) may be prepared by self-assembly in acetonitrile solution at 100 °C ( 1 , 3 ) or without solvent at 20 °C ( 2 ). All three contain [CuCN] chains that are bridged by the bidentate aromatic ligands into sheets in 1 and 3 D frameworks in 2 and 3 . Reaction of CuSCN with these heterocyclic diazines at 100 °C leads to formation of the lamellar coordination polymers [(CuSCN)(μ-2 Mepyz)] ( 4 ) and [CuSCN · (4 Mepym-κN1)] ( 5 ), which contain respectively [CuSCN] chains and trans-trans fused [CuSCN] sheets as substructures. The presence of an asymmetric substitution pattern in 2 Mepyz and 4 Mepym induces the adoption of a chiral structure by 2 and 5 (space groups P2₁2₁2₁ and P1).     

Copper(I) Coordination Polymers with Alkanedithiol and ‐dinitrile Bridging Ligands

CuI‐based coordination polymers with 1, 2‐ethanedithiol, 3, 6‐dioxa‐1, 8‐octanedithiol and 3‐oxa‐1, 5‐pentanedinitrile as respectively μ‐S, S′ and μ‐N, N′ bridging ligands have been prepared by reaction of CuI with the appropriate alkane derivative in acetonitrile. equation/tex2gif-stack-1.gif[Cu(HSCH₂CH₂SH)₂]I ( 1 ) contains 4⁴ cationic nets, equation/tex2gif-stack-2.gif[(CuI)₂(HSCH₂CH₂OCH₂CH₂OCH₂CH₂SH)] ( 2 ) neutral layers in which stairlike CuI double chains are linked by dithiol spacers. In contrast to these 2D polymers, equation/tex2gif-stack-3.gif[CuI(NCCH₂CH₂OCH₂CH₂CN)] ( 3 ) and equation/tex2gif-stack-4.gif[(CuI)₄(NCCH₂CH₂OCH₂CH₂CN)₂] ( 4 ) both contain infinite chains with respectively (CuI)₂ rings and distorted (CuI)₄ cubes as building units. Solvothermal reaction of CuI with the thiacrown ether 1, 4, 10‐trithia‐15‐crown‐5 (1, 4, 10TT15C5) in acetonitrile affords the lamellar coordination polymer equation/tex2gif-stack-5.gif[(CuI)₃(1, 4, 10TT15C5)] ( 7 ) in which copper atoms of individual CuI double chains are bridged in a μ‐S1, S4 manner. The third sulphur atom S10 of the thiacrown ether coordinates a copper(I) atom from a parallel chain to generate a 2D network.     

Tetramethylcyclotetraarsoxane Bridging of Copper(I) Halide Units Cu6Br6, Cu2I2, [Cu6I8]2–, and [Cu3I4–] in Porous Coordination Polymers

The polymeric compounds [{Cu₂I₂(C₆H₅CN)₂[cyclo‐(CH₃AsO)₄]} · C₆H₅CN] ( 1 ) and [Cu₆Br₆(C₆H₅CN)₄{cyclo‐(CH₃AsO)₄}] ( 2 ) may be prepared by reaction of the copper(I) halide with methylcycloarsoxane (CH₃AsO)_n in benzonitrile at 100 °C. 1 contains four‐membered (CuI)₂ rings, 2 tricyclic Cu₆Br₆ units, that are connected through bridging (CH₃AsO)₄ ligands into infinite chains. π–π Stacking of terminal C₆H₅CN ligands from parallel chains leads to the construction of porous frameworks, whose cavities are large enough in the case of 1 to accommodate guest C₆H₅CN molecules. In the presence of CsI, the self‐assembly reaction of CuI with (CH₃AsO)₄ in H₂O–CH₃OH–CH₃CN (at 20 °C) or CH₃CN (at 130 °C) affords [Cs(H₂O)₂][Cu₃I₄{cyclo‐(CH₃AsO)₄}₂] · 0.5 CH₃OH ( 3 ) and Cs[Cu₃I₄{cyclo‐(CH₃AsO)₄}₂] ( 4 ), whose 1‐ and 2‐dimensional anionic coordination polymers are linked together through respectively [Cs{cyclo‐(CH₃AsO)₄‐κ⁴O}₂]⁺ and [Cs{Cu₃I₄‐κ⁴I}{cyclo‐(CH₃AsO)₄‐κ⁴O}] sandwiches.     

Synthesis,Crystal Structures,and Properties of the Copper(I) Halide Coordination Polymers 2[CuX(μ‐2‐chloropyrazine‐N,N')] (X = Cl,Br), 1[CuI(2‐chloropyrazine‐N)], and [Cu2I2(2‐chloropyrazine)]

The new copper coordination polymers 2[CuX(μ‐2‐chlor‐opyrazine‐N, N')] (X = Cl ( I ), Br ( II ), 1[CuI(2‐chloropyrazine‐N)] ( III ) and [Cu₂I₂(2‐chloropyrazine)] ( IV ) has been prepared by the reaction of the copper(I) halides with 2‐chloropyrazine at roomtemperature or under hydrothermal conditions. The crystal structures of the 1:1 compounds I and II consist of zig‐zag CuX single chains running parallel to the crystallographic a‐axis which are linked by the 2‐chloropyrazine spacer molecules to sheets parallel to (010). For the iodine compound III a one‐dimensional structure is found which consists of CuX double chains running parallel to the crystallographic a‐axis. The thermic properties of all compounds were investigated in different gas atmospheres using simultaneously differential thermal analysis and thermogravimetry (DTA‐TG) as well as temperature resolved X‐ray powder diffraction. On heating, the 1:1 compounds I and II decompose directly to the corresponding copper(I) Halides, whereas the thermal decomposition of III occcur via IV as an intermediate.     

[B(O–C6H4–CN)4]– based Silver and Copper Coordination Polymers

A series of new coordination polymers bearing the [B(O–C₆H₄–CN)₄]^– anion was synthesized. Two new, one dimensional coordination frameworks of the type M[B(O–C₆H₄–CN)₄] (M = Ag, Cu) were obtained by salt metathesis. The reactivity towards organic Lewis‐bases was studied. The reaction with bidentate ligands yielded two dimensional networks with the general formula [M(L)][B(O–C₆H₄–CN)₄] {L = 2,2′‐bipyridine, 4,4′‐bipyridine, 1,2‐bis(pyridyl)ethane, 1,4‐diazabicyclo[2.2.2]octane}. The synthesis, properties and single crystal structure are reported.     

Syntheses and Structures of Three New Copper(II) Coordination Polymers Involving 2, 2‐(4, 6‐Dinitro‐1, 3‐phenylenedioxy)­diacetic Acid

Three copper(II) coordination polymers, namely, {[CuL(H₂O)₂] · 4H₂O}_n( 1 ), [CuL(H₂O)(DMF)]_n( 2 ), and [CuL(2, 2′‐bipy)(DMSO)] · DMSO ( 3 ) [H₂L = 2, 2′‐(4, 6‐dinitro‐1, 3‐phenyl‐enedioxy)diacetic acid] were synthesized in different solvents (H₂O, DMF, and DMSO). X‐ray single crystal diffraction studies show that both complexes 1 and 3 belong to triclinic crystal system and P$\bar{1}$ space group and complex 2 belongs to the monoclinic crystal system and P2₁/c space group. In three complexes, all the central Cu^II ions coordinate with the ligand, forming a square pyramidal configuration. Both complexes 1 and 2 show similar 1D chain‐like structure and the chains are further connected by hydrogen bonds, forming 3D frameworks. Complex 3 exhibits a 0D structure due to the introduction of the ligand 2, 2′‐bipy. In addition, the luminescence properties of these complexes were investigated.     

Platinum(II) and Palladium(II) Halides and Pseudohalides with the Ligand Tri(1‐cyclohepta‐2, 4, 6‐trienyl)phosphane. X‐Ray Structural Analysis of [P(C7H7)2(η2‐C7H7)]PtI2

Tri(1‐cyclohepta‐2, 4, 6‐trienyl)phosphane, P(C₇H₇)₃ ( 1 ) ([P] when coordinated to a metal) stabilizes platinum(II) ( 2 ) and palladium(II) dihalides ( 3 ) as [P]MX₂ with X = Cl ( a ), Br ( b ) and I ( c ). The phosphane coordinates to the metal as a chelate ligand via both phosphorus and the central η²‐C=C bond of one of the cyclohepta‐2, 4, 6‐trienyl rings. The complexes were prepared by various routes, mainly by the reaction of (cod)MCl₂ (cod = cycloocta‐1, 5‐diene) with 1 to give the chlorides 2a and 3a , which then could be converted into the bromides 2b , 3b or the iodides 2c , 3c by reaction with NaBr or NaI, respectively. The molecular structure of 2c was determined by X‐ray analysis. Treatment of 2a and 3a with sodium or potassium salts of several pseudohalides afforded the complexes [P]MX₂ 2d (NCO/NCO), 2e₁ (NCS/SCN), 2e₁' (SCN/NCS), 2f₂ (SeCN/SeCN), 3f₁ (NCSe/SeCN), 2g and 3g (X = N₃). Attempts failed to synthesize the cyanides 2h and 3h by the same route. By using an excess of trimethylsilyl cyanide in the reaction with 2a in THF solution, the complex trans‐{[(C₇H₇)₃P]₂Pt(CN)₂} ( 4h ) was obtained instead of 2h . The analogous complexes trans‐{[(C₇H₇)₃P]₂MX₂} with M = Pt ( 4 ) and Pd ( 5 ) for X = Cl ( a ), Br ( b ), I ( c ) could be prepared from the reaction of the corresponding tetrahalogenometallates and 1 (in the case of 5c from PdI₂ and 1 ). In contrast to 4h , the complexes 4a‐c and 5a‐c were found to be labile in solution with respect to partial loss of the phosphane 1 and rearrangement into 2a‐c and 3a‐c , respectively. All compounds were characterized by IR spectroscopy and by multinuclear magnetic resonance spectroscopy (¹H, ¹³C, ³¹P, ⁷⁷Se and ¹⁹⁵Pt NMR). The ligand [P] in 2 and 3 is fluxional with regard to coordination of the C₇H₇ rings to the metal.     

Synthesis of a One‐dimensional Coordination Polymer Based on Copper(II) Nitrate and 1,2‐Bis(5‐monomethylhydrazinyl‐1H‐tetrazolyl)ethane

A one‐dimensional coordination polymer based on copper(II) nitrate and 1,2‐bis(5‐monomethylhydrazinyl‐1H‐tetrazolyl)ethane as ligand was prepared. The thermal and physical stability was determined by differential scanning calorimetry and BAM methods. The polymer was investigated by vibrational spectroscopy and single X‐ray diffraction. Moreover, the ligand itself and the 1,2‐bis(1H‐tetrazolyl)ethane were characterized as energetic material by bomb calorimetric measurements along with calculations using the EXPLO5 software. Both compounds have moderate energetic properties along with a high thermal and physical stability. These findings render these compounds into promising environment friendly gas generating agents.     

Assemblies of 1D and 2D Copper(II) Chiral Coordination Polymers by Salicylaldehyde Schiff Bases: Synthesis,Crystal Structures,and Magnetic Properties

Reaction of CuCl₂ · 2H₂O with chiral Schiff bases and sodium dicyanamide led to the formation of two chiral copper(II) coordination polymers, namely [Cu₄(L¹)₂(dca)₄]_n ( 1 ) and [Cu₂(L²)(μ‐Cl)(dca)(H₂O)]_n · nH₂O ( 2 ) {H₂L¹ = (1R, 3S)‐N′,N′′‐bis[salicylidene]‐1,3‐diamino‐ 1,2,2‐trimethylcyclopentane, H₂L² = (1R, 3S)‐N′,N′′‐bis[3‐ethoxysalicylidene]‐1,3‐diamino‐ 1,2,2‐trimethylcyclopentane, dca = dicyanamide}. Both complexes were structurally characterized by elemental analyses, IR spectroscopy and single‐crystal X‐ray diffraction. Complex 1 exhibits a two‐dimensional polymeric structure formed by single dca bridging tetranuclear Cu₄ units. Complex 2 displays a left‐handed helical chain structure constructed from Cu₂ dimers with single dca bridges. The chirality of 1 and 2 was confirmed by circular dichroism (CD) measurements in solution. Both complexes exhibit strong antiferromagnetic couplings with J = –308(4) cm^–1 for 1 and J = –123(1) cm^–1 for 2 in 2–300 K.     

Syntheses,Structures, and Catalytic Properties of Three Copper(II) Coordination Polymers Based on 2,3,5,6‐Tetrafluoro‐1,4‐bis(triazole‐ylmethyl)benzene and Benzene Carboxylate Ligands

Three new mixed‐ligand coordination polymers of Cu^II, namely, [Cu(Fbtx)(L1)(H₂O)]_n ( 1 ), [Cu(Fbtx)_0.5(HL2)(H₂O)₂]_n ( 2 ), and {[Cu(Fbtx)_1.5(HL3)(H₂O)] · H₂O}_n ( 3 ) [Fbtx = 2,3,5,6‐tetrafluoro‐1,4‐bis(1,2,4‐triazole‐1‐ylmethyl)benenze, H₂L1 = terephthalic acid, H₃L2 = trimesic acid, NaH₂L3 = 5‐sulfoisophthalic acid monosodium salt], were hydrothermally synthesized and structurally characterized by elemental analysis, IR spectra, and single‐crystal and powder X‐ray diffraction techniques. All the complexes have a two‐dimensional (2D) coordination layer structure. Of these, 1 displays a planar 4⁴‐ sql structure whereas both 2 and 3 are highly undulated 6³‐ hcb nets. Moreover, their thermal stability and catalytic behaviors in the aerobic oxidation of 4‐methoxybenzyl alcohol were also investigated as well. The results indicate that the benzene dicarboxylate ligands have an effective influence on the structures and catalytic properties of the resulting coordination polymers.     

Two Zinc(II) Coordination Polymers Based on the Ligand 1, 4‐Bis[(2‐methyl‐imidazol‐1‐yl)methyl]benzene: Syntheses,Crystal Structures and Properties

Two coordination polymers (CPs), {[Zn₂(BMB)(5‐AIPA)₂] · 2H₂O}_n( 1 ) and [Zn(BMB)(5‐NIPA)]_n( 2 ) {BMB = 1, 4‐bis[(2‐methyl‐imidazol‐1‐yl)methyl]benzene, 5‐AIPA = 5‐aminoisophthalic acid, 5‐NIPA = 5‐nitroisophthalic acid}, were synthesized under hydrothermal conditions. Compound 1 displays a 2D double‐layer structure, which is packed into a 3D supramolecule by interlayer hydrogen bonds and π–π stacking interactions. Compound 2 displays a threefold interpenetrating 3D network, which is composed of left‐handed helical chains and two types of meso‐helical chains along different directions.     

Syntheses,Structures, and Luminescent Properties of d10 Coordination Polymers with 2‐(4‐Carboxyphenyl)‐imidazo[4, 5‐f]‐1, 10‐phenanthroline and 1, 3‐Benzenedicarboxylate Derivatives

Four Zn^II/Cd^II coordination polymers (CPs) based on 2‐(4‐carboxy‐phenyl)imidazo[4, 5‐f]‐1, 10‐phenanthroline (HNCP) and different derivatives of 5‐R‐1, 3‐benzenedicarboxylate (5‐R‐1, 3‐BDC) (R = NO₂, H, OH), [Zn(HNCP)(5‐NO₂‐1, 3‐BDC)]_n ( 1 ), [Cd(HNCP)(5‐NO₂‐1, 3‐BDC)]_n ( 2 ), [Zn(HNCP)(1, 3‐BDC)(H₂O)₂]_n ( 3 ), and {[Zn(HNCP)(5‐OH‐1, 3‐BDC)(H₂O) · H₂O}_n ( 4 ) were synthesized under hydrothermal conditions. Compounds 1 – 4 were determined by elemental analyses, IR spectroscopy, and single‐crystal and powder X‐ray diffraction. Compounds 1 and 2 are isomorphous, presenting a 4‐connected uninodal (4, 4)‐sql 2D framework with threefold interpenetration, which are further extended into the three‐dimensional (3D) supramolecular architecture through π ··· π stacking interactions between the aryl rings of 5‐NO₂‐1, 3‐BDC. Compared to compound 1 , 3 is obtained by using different reaction temperatures and metal‐ligand ratios, generating a 3D framework with –ABAB– fashion via π ··· π stacking interactions. Compound 4 is a 1D chain, which is further extended into a 3D supramolecular net by hydrogen bonds and π ··· π stacking interactions. The thermogravimetric and fluorescence properties of 1 – 4 were also explored.     

Lamellar Copper(I) Thiocyanate‐Based Coordination Polymers containing the Alkali Cation ligating Thiacrown Ether 1,10‐Dithia‐18‐crown‐6

The lamellar coordination polymer [(CuSCN)₂(μ‐1,10DT18C6)] (1,10DT18C6 = 1,10‐dithia‐18‐crown‐6), in which staircase‐like CuSCN double chains are bridged by thiacrown ether ligands, may be prepared in two triclinic modifications 1 a and 1 b by reaction of CuSCN with 1,10DT18C6 in respectively benzonitrile or water. Performing the reaction in acetonitrile in the presence of an equimolar quantity of KSCN leads, in contrast, to formation of the K⁺ ligating 2‐dimensional thiocyanatocuprate(I) net [{Cu₂(SCN)₃}^–] of 2 , half of whose Cu(I) atoms are connected by 1,10DT18C6 macrocycles. The potassium cations in [{K(CH₃CN)}{Cu₂(SCN)₃(μ‐1,10DT18C6)}] ( 2 ) are coordinated by all six potential donor atoms of a single thiacrown ether in addition to a thiocyanate S and an acetonitrile N atom. Under similar conditions, reaction of CuI, NaSCN and 1,10DT18C6 affords [{Na(CH₃CN)₂}{Cu₄I₄(SCN)(μ‐1,10DT18C6)}] ( 3 ), which contains distorted Cu₄I₄ cubes as characteristic molecular building units. These are bridged by thiocyanate and thiacrown ether ligands into corrugated Na⁺ ligating sheets. In the presence of divalent Ba²⁺ cations, charge compensation requirements lead to formation of discrete [Cu(SCN)₃(1,10DT18C6‐κS)]^2– anions in [Ba{Cu(SCN)₃(1,10DT18C6‐κS)}] ( 4 ).     

Synthesis,Crystal Structures,and Thermal Analyses of ­Copper(II) and Manganese(II) Mixed‐Ligand Coordination Polymers Constructed from Benzimidazole‐5, 6‐dicarboxylic Acid and N‐Donor Ligands

The coordination polymers, {[Cu(Hbidc)(2, 2′‐bpy)(H₂O)] · 2H₂O}_n ( 1 ) and {[Mn(Hbidc)(2, 2′‐bpy) (H₂O)₂] · 2H₂O}_n ( 2 ) (H₃bidc = benzimidazole‐5, 6‐dicarboxylic acid, 2, 2′‐bpy = 2, 2′‐bipyridine), were synthesized in solution and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), and single‐crystal X‐ray diffraction. Complexes 1 and 2 consist of different 1D chain structures. In both compounds, 2, 2′‐bpy is chelating in a bidentate manner, whereas the Hbidc ligands in complexes 1 and 2 display chelating‐bridging tridentate and bridging bidentate coordination modes. The two complexes are further extended into 3D supramolecular structures through O–H ··· O and N–H ··· O hydrogen bonds. The thermal stabilities of complexes 1 and 2 were studied by thermogravimetric analyses (TGA).     

Syntheses,Crystal Structures,and Photocatalytic Activities of Three Copper Coordination Polymers Based on Bis(1H‐imidazol‐4‐yl)benzene/3‐(2‐Pyridyl)pyrazole

Three copper(II) coordination polymers (CuCPs), namely, [Cu_0.5(1,4‐bib)(SO₄)_0.5]_n ( 1 ), {[Cu(1,3‐bib)₂(H₂O)] · SO₄ · H₂O}_n ( 2 ), and [Cu(bpz)(SO₄)_0.5]_n ( 3 ), were assembled from the reaction of three N‐donors [1,4‐bib = 1,4‐bis(1H‐imidazol‐4‐yl)benzene, 1,3‐bib = 1,3‐bis(1H‐imidazol‐4‐yl)benzene, and Hbpz = 3‐(2‐pyridyl)pyrazole] with copper sulfate under hydrothermal conditions. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectroscopy, powder X‐ray diffraction (PXRD), and thermogravimetric analyses (TGA). Structure analyses reveal that complex 1 is a 3D 6‐connected {4¹² · 6³}‐ pcu net, complex 2 is a fourfold 3D 4‐connected 6⁶‐ dia net, whereas complex 3 is a 1D snake‐like chain, which further expanded into 3D supramolecular architectures with the help of C–H ··· O hydrogen bonds. Moreover, the photocatalytic tests demonstrate that the obtained CuCPs are photocatalysts in the degradation of MB with the efficiency is 86.4 % for 1 , 75.3 % for 2 , and 91.3 % for 3 after 2 h, respectively.     

Synthesis and Luminescent Properties of Two Zinc(II) Coordination Polymers Constructed by 4‐(Pyridin‐4‐ylmethoxy)benzolic Acid Ligand

Two coordination polymers, namely [Zn(L)Cl] ( 1 ) and [Zn(L)₂] ( 2 ) [L = 4‐(pyridin‐4‐ylmethoxy)benzolic acid] were synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction analyses, powder X‐ray diffraction, and thermogravimetric analysis. Compounds 1 and 2 have a two‐dimensional square‐shaped structure (the dimensions are 15.43 × 15.43 Å for 1 and 12.064 × 15.017 Å for 2 ) with (4⁴ · 6²) topology. Moreover, compounds 1 and 2 exhibit a 3D supramolecular structure made up by strong π–π interactions from the adjacent layers. Furthermore, compounds 1 and 2 show good fluorescence properties in the solid state at room temperature.     

Synthesis,Structures, and Magnetic Properties of New Thiocyanato Coordination Polymers with 4‐(3‐Phenylpropyl)pyridine as Ligand

The reaction of different metal salts with 4‐(3‐phenylpropyl)pyridine (ppp) lead to the formation of compounds of composition M(NCS)₂(ppp)₄ [M = Mn ( Mn‐1 ); Fe ( Fe‐1 ), Ni ( Ni‐1 ); Cd ( Cd‐1 )], M(NCS)₂(ppp)₂(H₂O)₂ [M = Mn ( Mn‐2 ); Ni ( Ni‐2 )] and [M(NCS)₂(ppp)₂]_n [M = Mn ( Mn‐3 ); Ni ( Ni‐3 ); Cd ( Cd‐3 )]. On heating compounds M‐1 decompose without the formation of any ppp deficient intermediate. In contrast, on heating, Ni‐2 transforms into a compound of composition M(NCS)₂(ppp)₂ that does not correspond to Ni‐3 . Unfortunately, this compound is of low crystallinity and therefore, its structure cannot be determined. The crystal structures of compounds M‐1 and M‐2 consist of discrete complexes, in which the metal cations are octahedrally coordinated. In compounds M‐3 the metal cations are linked by pairs of μ‐1,3‐bridging anions into chains. IR spectroscopic investigations show, that the value of the asymmetric CN stretching vibration depend on the coordination mode of the anionic ligand as well as on the nature of the metal cation. Magnetic measurements reveal that Ni‐3 shows only Curie‐Weiss behavior without any magnetic anomaly. A similar behavior is also found for Ni‐3 . Comparison of the magnetic properties of Ni‐3 with those of similar compounds indicates that the magnetic properties are only minor influenced by the Co‐ligand.     

Luminescent Thermochromism of 2D Coordination Polymers Based on Copper(I) Halides with 4‐Hydroxythiophenol

Solvothermal reactions between copper(I) halides and 4‐mercaptophenol give rise to the formation of three coordination polymers with general formula [Cu₃X(HT)₂]_n (X=Cl, 1 ; Br, 2 ; and I, 3 ). The structures of these coordination polymers have been determined by X‐ray diffraction at both room‐ and low temperature (110 K), showing a general shortening in Cu?S, Cu?X and Cu?Cu bond lengths at low temperatures. 1 and 2 are isostructural, consisting of layers in which the halogen ligands act as μ₃‐bridges joining two Cu1 and one Cu2 atoms whereas in 3 the iodine ligands is as μ₄‐mode but the layers are quasi‐isostructural with 1 or 2 . These compounds show a reversible thermochromic luminescence, with strong orange emission for 1 and 2 , but weaker for 3 at room temperature, whereas upon cooling at 77 K 1 and 2 show stronger yellow emission, and 3 displays stronger green emission. DFT calculations have been used to rationalize these observations. These results suggest a high potential for this novel and promising stimuli‐responsive materials.     

Alkali Cation Ligating Chains and Sheets of the Macrocycle 1, 7‐Dithia‐18‐Crown‐6 with Bridging Iodo‐ and Thiocyanatocuprate(I) Units

Treatment of an acetonitrile solution of CuI with 1, 7‐dithia‐18‐crown‐6 (1, 7‐DT18C6) at 100°C affords the coordination polymer ¹[(CuI)₂(1, 7‐DT18C6)₂] ( 1 ) in which 1, 7‐DT18C6 ligands bridge (CuI)₂ rings into double chains. 1D polymers of the type ¹[M{(Cu₃I₄)(1, 7‐DT18C6)}] (M = K, 2 ; M = Cs, 3 ) can be isolated under similar conditions in the presence of respectively KI and CsI. Both contain bridging heptacyclic [Cu₆I₈]^2— units but crystallise in different space groups, namely P1 and C2/m. The cesium cation of 3 is markedly displaced from the best plane through the thiacrown ether donor atoms. Reaction of 1, 7‐DT18C6 with CuSCN in the presence of NaSCN yields ²[{Na(CH₃CN)₂} {(CuSCN)₂(1, 7‐DT18C6)}][Cu(SCN)₂] ( 4 ), in which ¹[(CuSCN)₂] double chains are linked through macrocycles into sheets. Infinite ¹[{Cu(SCN)₂}^—] chains compensate the charge of the Na⁺ cations. Complex 1 can imbibe 0.90 mol CsNO₃ per mol of 1, 7‐DT18C6 pairs.