Masahiko Maekawa

Framework dimensionality of copper(I) coordination polymers of 4,4′-bipyrimidine controlled by anions and solvents

The reaction of [Cu(C2H4)n]NO3 with 4,4′-bipyrimidine (bpm) in Me2CO under C2H4 afforded a polymeric Cu(I)–bpm/C2H4 adduct [Cu2(bpm)(C2H4)(NO3)2]n (1) with an infinite 1-D zigzag chain structure. Similar reactions of [Cu(C2H4)n]ClO4 or [Cu(MeCN)4]BF4 with bpm in Me2CO under C2H4 afforded Cu(I)–bpm/C2H4 adducts {[Cu3(bpm)2(C2H4)2](ClO4)3}n (2) and {[Cu3(bpm)2(C2H4)2]–(BF4)3}n (3), respectively, which have an infinite 1-D zigzag ladder structure. It is interesting that two disordered ClO4− or BF4− anions are accommodated in the inside cavity of the ladder chains. In contrast, the reaction of [Cu(MeCN)4]BF4 with bpm in MeOH under C2H4 afforded a Cu(I)–bpm/C2H4 adduct {[Cu4(bpm)3(C2H4)3(MeOH)](BF4)4·2H2O·3MeOH}n (4). Three Cu atoms are bridged by three bpm ligands to form a metallacalix[3]arene structure with three legs of C2H4. Furthermore, these metallacalix[3]arenes are linked through another Cu atom in the terminal N atom of bpm to produce a chiral 2-D sheet structure with space groupP63. One BF4− anion is accommodated in the small triangular Cu3 cavities, whereas three disordered BF4− anions are encapsulated in the large triangular Cu3 cavities. In contrast to complex 4, [Cu(MeCN)4]BF4 was reacted with bpm in MeOH under Ar, and C2H4 gas was then bubbled into the resultant brown suspensions. The reaction solution was allowed to come to room temperature, and Cu(I)–bpm complex {[Cu3(bpm)3](SiF6)1.5}n (5) was collected. The tetrahedral Cu atom is coordinated by two N atoms in the chelate site of bpm and two N atoms in the terminal sites of two other bpm ligands to form two racemic metallacalix[3]arene structures. It is noteworthy that these metallacalix[3]arenes are joined through the bpm ligands to afford a 3-D cage structure consisting of two right-handed and left-handed helix networks. One disordered SiF62− anion is accommodated in the inside cavity between two opposite metallacalix[3]arene structures. On the basis of these results, it has been concluded that BF4−, PF6−, ClO4− and SiF62− anions can serve as anion templates to self-assemble polymeric Cu(I) C2H4 adducts and a cage compound in complexes 2–5. The NO3− anion is ineffective as an anion template, as indicated by the higher coordination ability of the NO3− anion in complex 1. Additionally, solvent-dependent effects have been observed in the formation process: Me2CO can preferentially induce polymeric 1-D chain and 1-D ladder structures in complexes 1–3, whereas MeOH can produce 2-D sheet and 3-D cage structures by the linkage of metallacalix[3]–arene structures in complexes 4 and 5.

Silver(I) complexes of dibenzo-18-crown-6-ether having cation–π and π–π interactions

Three silver(I) complexes of dibenzo-18-crown-6-ether (DB[18]C6), [Ag(DB[18]C6)(ClO 4 )](THF) ( 1 ), [Ag(DB[18]6)(CF 3 SO 3 )] 2 (acetone) 2 ( 2 ) and [Ag(DB[18]C6)(CF 3 COO)] 2 (AgCF 3 COO) 2 ( 3 ) have been synthesized in different solvents and characterized structurally. In each complex, silver ions prefer an octahedral coordination geometry and form close dinuclear complex with DB[18]C6 based on cation–π interaction in η 2 -fashion. In particular, the coordination unit involving σ bonding at an oxygen group and π–π bonding between two benzene rings is quite unique.

A zigzag chain coordination polymer consisting of silver(I) ion having square planar geometry

Abstract Silver(I) complexes of hexakis(tolylsulfanyl)benzene (htsb), [Ag(htsb)](PF6) (1), have been prepared and their molecular structures were determined by X-ray crystallography. In 1, the silver ion prefers a square planar coordination geometry comprized of four S atoms from two different htsb molecules and producing a zigzag chain structure of Ague5f8S in the silver coordination polymer. Based on the thermo-gravimetry analysis results, two tolylsulfanyl groups were easily eliminated at approximately 211xa0°C. However, [Ag(htsb)(2-butanone)] (PF6) (2), which were obtained by the reactions in different solvents, showed a different colors and thermal degradation behaviors.

Porous silver(I) organometallic coordination polymer of triptycene, and the guest desorption and absorption

Abstract On the basis study of porous silver(I) complex of triptycene (tpty), [Ag3(tpty)3(ClO4)3](toluene)2 (1), its toluene desorbed complex (2) and absorbed complex (3) have been synthesized and confirmed by 1H NMR spectra and X-ray powder diffraction. In complex 1, a 3D architecture with triptycene exhibits an unprecedented μ–η2–η2 or μ–η2–η2–η1 coordination mode depending on the steric requirements of the network. The desorption and absorption of guest molecules occur in this complex accompanying the structure change. The potential study of these complexes for the rational control and synthesis of porous organometallic coordination network is discussed.

Intervalence charge-transfer system by 1D assembly of new mixed-valence octanuclear CuI/CuII/CuIII cluster units.

The reaction of Cu(Hm-dtc)(2), Br(2), and CuBr(2) yielded a new mixed-valence octanuclear Cu(I)/Cu(II)/Cu(III) cluster, encapsulating a Br anion in the center of the cluster cage. The octanuclear cluster units form a 1D assemblage, which induces intervalence charge-transfer transitions from Cu(II) ions to Cu(III) ions between the clusters.

Dinuclear silver(I) complexes of dibenzo-crown ethers and the mononuclear complex of aminobenzo-crown ether

Abstract Three silver(I) coordination complexes of crown ethers, [Ag([15]C6)(ClO4)2](THF) (1), [Ag(DB[21]C7)(H2O)]2(ClO4)2 (2) and [Ag(DB[24]C8)(CF3SO3)]2(acetone)2 (3) have been synthesized in different solvents and characterized structurally. The mononuclear complex 1 and two different dinuclear complexes 2 and 3 are shown in this work. Silver(I) ions are situated in a distorted pentagonal pyramidal geometry and form close dinuclear complex with DB[21]C7 based on cation–π interaction in η2-fashion. This coordination unit involves σ bonding at a part oxygen atoms of ligand oxygen base cavity and π–π interaction between two parallel phenyl groups. But in 3, each DB[24]C8 host contained two silver(I) ions as guest without cation–π and π–π interaction.

A novel 2-D silver(I)–acyclic polyene coordination polymer assembled with linear unsaturated bridges

Abstract A novel 2-D silver(I) coordination polymer of 1,8-diphenylocta-1,3,5,7-tetraene was synthesized, and characterized by X-ray single crystal analysis. Reaction of 1,8-diphenylocta-1,3,5,7-tetraene (dpot) with silver(I) perchlorate at 60xa0°C afforded [Ag2(dpot)(ClO4)2]n (1). In this structure, silver(I) adopts a distorted tetrahedral geometry and the dpot molecules link the silver(I) ions in a trans-μ-tetra-η2 manner to generate 1-D chains with metallocyclophane motifs. Further, the silver(I) ions between the two neighboring chains are bridged by perchlorate groups to give a novel 2-D (3,4)-connected polymeric network with (4,62)2(42,62,82) topology. Additionally, the main plane of the phenyl moiety makes an angle of 33.08° with the topology through the polyene portion in 1, and thus the coordination of silver(I) to dpot results in the distortion of the dpot molecule. To the best of our knowledge, this is the first example of a silver(I) complex with acyclic polyene.

Structural controls of 2D sheet copper(I) ethylene and carbonyl coordination polymers directed by anions and solvents

The reactions of Cu(I) ion with {BF4−, ClO4−, or PF6−} anions and 6,6′-dimethyl-4,4′-bipyrimidine (Me2bpm) under C2H4 or CO in MeOH preferentially afforded three 2D sheet Cu(I)–Me2bpm/{C2H4, CO} adducts [Cu4(Me2bpm)3(C2H4)3(MeCN)](BF4)4·0.33MeOH}n (2), {[Cu4(Me2bpm)3-(C2H4)3(MeOH)0.33](ClO4)4}n (3), and {[Cu4(Me2bpm)3(CO)3(MeCN)](PF6)4·0.33MeCN}n (4), whereas the similar reaction of Cu(I) ion with a BF4− anion and Me2bpm under CO in MeOH gave the metallamacrocyclic tetranuclear Cu(I)–Me2bpm/CO adduct [Cu4(Me2bpm)4(CO)4]-(BF4)4·4MeOH (5). In Cu(I)–Me2bpm/{C2H4, CO} adducts 2–4, it should be noted that the metallacalix[3]arene structures of the [Cu3(Me2bpm)3]3+ framework are linked through another Cu atom with MeCN (2 and 4) or MeOH (3) to produce a chiral 2D sheet structure with small Cu3 and large Cu9 cavities. In the small triangular Cu3 cavities, one MeOH (2) or MeCN (4) molecule is encapsulated in complexes 2 and 4, whereas these Cu3 cavities are empty in complex 3. In the large Cu9 cavities, one anion (X = BF4− (2), ClO4− (3) or PF6− (4)) is surrounding by six Me groups of three Me2bpm on the upside and three anions (X) are functionally accommodated on the downside for complexes 2–4, respectively. In the Cu(I)–Me2bpm/CO adduct 5, two of the four BF4− anions are accommodated in the upper and lower cavities of the [Cu4(Me2bpm)4] framework. We demonstrated that the metallamacrocyclic and polymeric 2D sheet Cu(I)–Me2bpm/{C2H4, CO} adducts can be reasonably self-assembled under the direction of anions and solvents.

Bowl–shaped Cu(I) metallamacrocyclic ethylene and carbonyl adducts as structural analogues of organic calixarenes

Three novel Cu(I) metallacalixarenes with C(2)H(4) and CO legs, in which an anion is accommodated in the inside cavity, were self-assembled by anion templation and have been structurally characterized.

Syntheses and structural studies on silver(I) coordination polymers with trans,trans-1,4-dipenyl-1,3-butadiene

For the purpose of investigation on the reactivity of silver(I) with multiphenyl diene and the effect of counteranions on silver(I) complexes, we selected several silver(I) salts to react with trans , trans -1,4-diphenyl-1,3-butadiene (dpbd). The treatment of AgClO 4 ·H 2 O with dpbd afforded a 1-D W-type chain silver(I) coordination polymer [Ag(dpbd)(ClO 4 )] ( 1 ) and while the reaction of AgCF 3 CO 2 with dpbd gave rise to a co-crystallization structure [Ag 3 (CF 3 CO 2 ) 3 ]·(dpbd) ( 2 ) in which silver(I) and trifluoroacetate form a 1-D supramolecular ladder chain. The measurements of electric conductivity show that polymer 1 exhibits semiconductive behavior and while polymer 2 is an insulator. The effect of counteranions and steric hindrance on the formation of these silver(I) complexes is also discussed.