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1.
Anion-controlled endo- and exocyclic complexes were afforded in the reactions of an S(2)O(3) macrocycle with AgPF(6) and AgClO(4), respectively. The two coordination modes that provide the Ag ion position inside (by PF(6)(-)) or outside (by ClO(4)(-)) the macrocyclic cavity are explained by the anion-coordination ability toward the metal cation. Furthermore, each Ag center bridges two ligands via a regular coordinative bond or by pi coordination, forming a cyclic dimeric-type product. NMR titrations of the complex system in solution were also carried out. 相似文献
2.
With the aim of gauging their potential as conducting or superconducting materials, we examine the crystal structures and magnetic properties of the roughly one hundred binary, ternary, and quaternary Ag(II) and Ag(III) fluorides in the solid state reported up to date. The Ag(II) cation appears in these species usually in a distorted octahedral environment, either in an [AgF](+) infinite chain or as [AgF(2)] sheets. Sometimes one finds discrete square-planar [AgF(4)](2-) ions. The Ag(III) cation occurs usually in the form of isolated square-planar [AgF(4)](-) ions. Systems containing Ag(III) (d(8)) centers are typically diamagnetic. On the other hand, the rich spectrum of Ag(II) (d(9)) environments in binary and ternary fluorides leads to most diverse magnetic properties, ranging from paramagnetism, through temperature-independent paramagnetism (characteristic for half-filled band and metallic behavior) and antiferromagnetism, to weak ferromagnetism. Ag(II) and Ag(III) have the same d-electron count as Cu(II) (d(9)) and Cu(III) (d(8)), respectively. F(-) and O(2-) ions are isoelectronic, closed-shell (s(2)p(6)) species; both are weak-field ligands. Led by these similarities, and by some experimental evidence, we examine analogies between the superconducting cuprates (Cu(II)/Cu(III)-O(2-) and Cu(II)/Cu(I)-O(2-) systems) and the formally mixed-valence Ag(II)/Ag(III)-F(-) and Ag(II)/Ag(I)-F(-) phases. For this purpose we perform electronic-structure computations for a number of structurally characterized binary and ternary Ag(I), Ag(II), and Ag(III) fluorides and compare the results with similar calculations for oxocuprate superconductors. Electronic levels in the vicinity of the Fermi level (x(2)-y(2) or z(2)) have usually strongly mixed Ag(d)/F(p) character and are Ag-F antibonding, thus providing the potential of efficient vibronic coupling (typical for d(9) systems with substantially covalent bonds). According to our computations this is the result not only of a coincidence in orbital energies; surprisingly the Ag-F bonding is substantially covalent in Ag(II) and Ag(III) fluorides. The electron density of state at the Fermi level (DOS(F)) for silver fluoride materials and frequencies of the metal-ligand stretching modes have values close to those for copper oxides. The above features suggest that properly hole- or electron-doped Ag(II) fluorides might be good BCS-type superconductors. We analyze a comproportionation/disproportionation equilibrium in the hole-doped Ag(II) fluorides, and the possible appearance of holes in the F(p) band. It seems that there is a chance of generating an Ag(III)-F(-)/Ag(II)-F(0) "ionic/covalent" curve crossing in the hole-doped Ag(II)-F(-) fluorides, significantly increasing vibronic coupling. 相似文献
3.
The ligand 4,4'-bipyrimidine combines a chelating bipyridine group and two terminal donor atoms into a single molecule; chelation to a single Ag(I) centre forms a square planar complex which can then form an extended planar ladder-type polymer by linking through linear Ag(I) centres whereas bis-coordination to an octahedral Co(II) centre yields a building block with four external donor nitrogen atoms which can coordinate to two distinct Ag(I) ions to form a heterometallic 2D net. 相似文献
4.
《Journal of Coordination Chemistry》2012,65(13):2307-2316
Two cobalt(II) coordination polymers [Co3(ttmb)2(H2O)6Cl6] · 3H2O (1) and Co(ttmb)2(H2O)2](NO3)2 · 4H2O (2) were synthesized by the reaction of 1,3,5-tri(1,2,4-triazol-1-ylmethyl)-2,4,6-trimethylbenzene (ttmb) and CoCl2 or Co(NO3)2. In 1, each ttmb shows a tri-monodentate coordination mode and bonds three Co(II)s to form a highly undulated 2-D network. The Schläfla symbol for the 2-D network is 3262. The highly undulated 2-D networks are not catenated, but interdigitate each other. In 2, each ttmb shows a two-monodentate coordination mode and connects two Co(II)s to extend a 2-D (4,4) network. The ttmb exhibits the cis,cis,cis-conformation in 1 and the cis,trans,trans-conformation in 2. The thermal stability of 1 was studied. 相似文献
5.
A homochiral amino acid coordination network [{Ag3Cu3(l-methioninato)6(NO3)3(H2O)3}.7H2O]n, self-assembled from CuII, AgI, and l-methionine via a distinct soft-hard recognition process, shows interesting characteristics, in that it is constructed from 1D helical building blocks and contains homochiral channels in which 1D water chains are hosted. This result provides an effective and controllable strategy for the preparation of enantiopure heterometallic supramolecular structures that are relevant to biopolymers. 相似文献
6.
WANG Jiang-yun GU Wen WANG Wen-zhen LIU Xin LIAO Dai-zheng 《高等学校化学研究》2006,22(3):283-286
Introduction Itiswell knownthatcyanogroupsincyanometa latessuchas[Ag(CN)2]-unitscanbeusedasbridg ingligandsandapolymericstructurecanbeformed throughsilver silver(argentophilic)interactions.This propertyhasbeenexploredintheconstructionofmany oligomericandp… 相似文献
7.
Son JH Pudenz MA Hoefelmeyer JD 《Dalton transactions (Cambridge, England : 2003)》2010,39(45):11081-11090
The ambiphilic molecule 8-(dimesitylboryl)quinoline (1) was synthesized by treatment of 8-bromoquinoline or 8-iodoquinoline with n-BuLi followed by dimesitylboronfluoride. Hydrolysis of 1 is unusually rapid compared to bulky triorganoboranes with the sequential loss of mesitylene and formation of mesityl(quinolin-8-yl)borinic acid (2) and 8-quinoline boronic acid dimer (3). Cooperativity within the bifunctional ambiphilic site leads to water activation and protodeboronation of the B-C(Mes) bonds. Blocking of the ambiphilic site of 1 by methylation of the quinoline nitrogen atom leads to an air-stable N-methyl-quinolinium salt. Coordination complexes were formed by reaction of 1 with CuCl, Ag(OTf), and PdCl(2)(PhCN)(2) with coordination of the quinolinyl nitrogen to the metal ion. The Cu(I) and Ag(I) centers are stabilized by η(3)-BC(ipso)C(ortho)π-interaction. The isolated Pd(II) complex is a product of cyclometalation, resulting from elimination of HCl upon deprotonation of the ortho-methyl group of nearby mesityl. The bonding in 7 could be understood as a 16-electron Pd complex that features an anionic η(3)-C(ipso)-C(ortho)-C(benzyl) allylic ligand fragment plus a Pd→B bond, or an η(4)-BC(ipso)-C(ortho)-C(benzyl) boratabutadiene anion fragment. 相似文献
8.
Maksymilian Ignaczak Andrzej Grzejdziak 《Monatshefte für Chemie / Chemical Monthly》1994,125(1):15-24
Summary Formation constants of the complexes of Ag(I) with 2-pyridine-carboxylic acid (Hpic) were determined by the potentiometric method: 01=36, 02=537. It was shown by IR spectroscopy that the complexation of Ag(I) ions in acetonitrile proceeds without the formation of Ag-O bond and the complexes have the following forms: AgHpic
+ and Ag(Hpic)
2
+
. Oxidation of Ag(Hpic)
2
+
at the potential =1850 mV vs. NHE resulted in the complex Ag(Hpic)
2
2+
. The formal potentialE
f
0
=1.772 V vs. NHE of the system Ag(Hpic)
2
2+
+eAg(Hpic)++Hpic was determined by chronovoltamperometry, while the formal potentialE
f
0
=1.841 V vs. NHE of the system Ag(Hpic)
2
2+
+eAg(Hpic)
2
+
was calculated. Properties of the system in water and acetonitrile were compared.
Charakteristik des Ag(II)/Ag(I)-Systems in Gegenwart von 2-Pyridincarbonsäure in Acetonitril
Zusammenfassung Es wurden die Bildungskonstanten der Komplexe von Ag(I) mit 2-Pyridincarbonsäure (Hpic) mittels Potentiometrie bestimmt: 01=36, 02=537. Die IR-Spektren bewiesen, daß die Komplexierung von Ag(I)-Ionen über die Ausbildung einer Ag-O-Bindung verläuft, wobei die Komplexe die folgenden Formeln besitzen: AgHpic + und Ag(Hpic) 2 + . Die Oxidation von Ag(Hpic) 2 + beim Potential =1850 mV gegenüber NHE ergab den Komplex Ag(Hpic) 2 2+ . Das formale PotentialE f 0 =1.772 V (gegenüber NHE) des Systems Ag(Hpic) 2 2+ +eAg(Hpic)++Hpic wurde mittels Chronovoltamperometrie ermittelt, während das formale PotentialE f 0 =1.841 V (gegenüber NHE) des Systems Ag(Hpic) 2 2+ +eAg(Hpic) 2 + berechnet wurde. Außerdem wurden die Eigenschaften der Systeme in Wasser und Acetonitril verglichen.相似文献
9.
Three coordination polymers, [Co(L)(tbta)]n (1), [Ag(L)(H2O)·(Hhpht)]n (2) and [Ag2(L)1.5(oba)]n (3) (L = 1,4-bis(2-methylbenzimidazol-1-ylmethyl)benzene, H2tbta = tetrabromoterephthalic acid, H2hpht = homophthalic acid, H2oba = 4,4′-oxybis(benzoic acid)), have been hydrothermally synthesized and structurally characterized. Complex 1 displays a 2-D uninodal 4-connected sql network, 2 and 3 feature chain structures, which further generate 2D supramolecular networks through hydrogen bonding interactions. The thermal and fluorescence properties of 1–3 have been carried out and discussed. 相似文献
10.
11.
Four cyano bridged Cu(II)–Pd(II) heterometallic complexes, [Cu(dpt)Pd(CN)4]n (1), {[Cu2(medpt)2Pd(CN)4](ClO4)2 · 3H2O}n (2), {[Cu2(dien)2Pd(CN)4](ClO4)2 · 2CH3OH}n (3) and {[Cu2(iPrdien)2Pd(CN)4](ClO4)2 · 2H2O}n (4) [dpt = 3,3′-iminobispropylamine; medpt = 3,3′-diamino-N-methyldipropylamine; dien = diethylenetriamine and iprdien = N′-isopropyldiethylenetriamine] have been synthesized and characterized by single crystal X-ray diffraction analysis, magnetic measurement and thermal study. Complexes 1, 2 and 3 are 1D coordination polymers, while 4 presents a 2D network. In 1, the cis-directed cyanide ligands of [Pd(CN)4]2− anions link two Cu(dpt) units to form a neutral coordination polymer, whereas in 2, 3 and 4, all the cyanide groups of [Pd(CN)4]2− take part in bonding with four adjacent Cu(II) ions, resulting in cationic coordination polymers counterbalanced by perchlorate anions. The structures are compared with those of analogous [Ni(CN)4]2− derivatives. The magnetic behavior shows antiferromagnetic interactions in all the complexes. 相似文献
12.
Reaction of the imidazolium N-heterocyclic carbene precursor containing a methyl-substituted pyridyl functionality [HCH3im(CH3py)]PF6, 1, with Ag2O produces the homoleptic Ag(I) complex, [Ag(CH3im(CH3py))2]PF6, 2. In a simple carbene transfer reaction the analogous Au(I) species, [Au(CH3im(CH3py))2]PF6, 3, is formed by treatment of 2 with Au(tht)Cl in dichloromethane. Both 2 and 3 are structurally similar with nearly linearly coordinated NHC ligands. The methyl group appended to the pyridyl ring inhibits rotation of the pyridyl group at room temperature. Addition of AgBF4 to a hot propionitrile solution of 3 followed by crystallization with diethyl ether yields the one-dimensional coordination polymer, {[AuAg(CH3im(CH3py))2(NCCH2CH3)](BF4)2}n, 4, which contains Au-Ag separations of 2.9845(5) and 2.9641(5) A with intermetallic angles of 167.642(14) degrees and 162.081(9) degrees. This material is intensely luminescent in the solid state and exhibits an emission band at 453 nm (lambdaex=350 nm). Nearly colorless [Pd(CH3im(CH3py))2Cl]PF6, 5, is produced upon treatment of 2 with PdCl2(NCC6H5)2. The Pd(II) center in 5 is coordinated to one NHC ligand in a chelate fashion, while the second NHC is bound solely through the carbon center. The X-ray crystal structures of 1-5 are reported. 相似文献
13.
14.
15.
One reaction system of Cu2+, dipn, and CN− with two different molar ratio sets of 1:1:5, and 2:1:8 produced two compounds 1 [CuII(dipn)][CuII(CN)4], and 2, respectively (dipn = dipropylenetriamine). Their structures were determined by X-ray crystallography. Compound 2 is built from Cu(I) and Cu(II) centers, which are bridged by cyanide groups and metal-metal bonds. The magnetic properties of 1 and 2 were investigated in 2-300 K. Compound 1 exhibits an antiferromagnetic exchange interaction between copper(II) ions mediated by cyano-bridges. 相似文献
16.
Rahman Bikas Hossein Farzaneh-Bonab Muhittin Aygün Marzieh Emami Tadeusz Lis 《Journal of Coordination Chemistry》2018,71(8):1127-1146
The hydrazone (E)-3-hydroxy-N’-(1-(2-oxo-2H-chromen-3-yl)ethylidene)-2-naphthohydrazide (H2L) was synthesized from the reaction of 3-acetylcoumarin and 3-hydroxy-2-naphthoic hydrazide in methanol. Compounds [Mn(H2L)(NO3)2(CH3OH)]·CH3OH (1a), [Mn(HL)(NO3)(CH3OH)]n (1b), [Co(HL)(NO3)(CH3OH)]n (2), and [Cu(HL)(NO3)] (3) were obtained by reaction of an equimolar amount of H2L with nitrate salts of Mn(II), Co(II), or Cu(II) in methanol. The reaction of ligand and Mn(NO3)2·4H2O was also carried out in the presence of sodium azide which led to the 1-D coordination polymer, [Mn(HL)(N3)(CH3OH)]n (4). All of the synthesized compounds were characterized by elemental analyses and spectroscopic methods. Single-crystal X-ray analysis of 1–4 indicated that H2L is neutral (in 1a) or mononegative ligand (in 1b, 2, 3 and 4). In 1b, 2 and 4 the 1-D polymeric chain is found by a rare coordination mode of this kind of hydrazone ligand since the naphtholic oxygen is coordinated to the neighboring metal ions while the NH moiety of hydrazone remains intact, also confirmed by FT-IR spectroscopic studies. The thermal stability of 2 and 4 were also studied from 30–1000 °C. 相似文献
17.
18.
Zhang S Pattacini R Braunstein P 《Dalton transactions (Cambridge, England : 2003)》2011,40(21):5711-5719
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. 相似文献
19.
Hori A Kataoka H Okano T Sakamoto S Yamaguchi K Fujita M 《Chemical communications (Cambridge, England)》2003,(2):182-183
The reversible cross-catenation of two different coordination rings (Pd(II)- and Pt(II)-linked rings) has been achieved by using the labile nature of the Pd-N interaction and efficient hydrophobic contact between the rings. 相似文献
20.
Maksymilian Ignaczak Andrzej Grzejdziak Ewa Degen-Piotrowska 《Monatshefte für Chemie / Chemical Monthly》1989,120(6-7):529-537
Summary Composition of complexes of Ag(II) and Ag(I) ions with 2,2:6,2-terpyridine (tp) have been established. It has been found that the Ag+ ion forms only one complex Ag(tp)+ withtp in acetonitrile; its conditional formation constant: 01=6.6·104 has been determined by the potentiometric method. Equilibria and redox systems formed in solutions due to the complexation of Ag+ and Ag2+ and oxidation of Ag(II) complexes are described. Their formal potentials have been found by coulometric and voltamperometric examinations. The presence of the Ag(tp)
2
3+
ion in the anodic oxidized solutions of the complexes Ag(tp)(NO3)2 and Ag(tp)2(NO3)2 has been proved. Properties of the system Ag(II)/Ag(I) in the presence of terpyridine in water and in acetonitrile have been compared.
Charakteristik der Systeme Ag(II)/Ag(I) in Gegenwart von 2,2:6,2-Terpyridin in Acetonitril
Zusammenfassung Die Zusammensetzung der Komplexe von Ag(I)- und Ag(II)-Ionen mit 2,2:6,2-Terpyridin (tp) wurde bestimmt. Das Ag+-Ion bildet mittp in Acetonitril nur einen Komplex-Ag(tp)+. Seine Konditionalbildungskonstante 01=6.6·104 wurde mit Hilfe der potentiometrischen Methode bestimmt. Es wurden die Gleichgewichte und Redoxsysteme als Resultat der Komplexbildung von Ag(II)- und Ag(I)-Ionen und der Ag(II)-Komplexoxidation charakterisiert und die Formalpotentiale mittels Voltametrie und Coulometrie bestimmt. Die Gegenwart der Ag(tp) 2 3+ -Ionen wurde in anodisch oxydierten Lösungen der Komplexe Ag(tp)(NO3)2 und Ag(tp)2(NO3)2 nachgewiesen. Die Eigenschaften des Systems Ag(II)/Ag(I) in Gegenwart von 2,2:6,2-Terpyridin in Wasser und in Acetonitril wurden verglichen.相似文献