缬沙坦类似物合成中间产物的捕获(I)(英文)

Valsartan[1], which is a very useful medicine in thetreatment of high-pressure blood, contains a tetrazolegroup. Its analogues exploration and complex actiontoward metal ions still remain very rare. As acontinuation of our in-situ [2 3] cycloaddition betw…     

Reactivity of Rhodium(I) Complexes Bearing Nitrogen-Containing Ligands toward CH(3)I: Synthesis and Full Characterization of Neutral cis-[RhX(CO)(2)(L)] and Acetyl [RhI(μ-I)(COMe)(CO)(L)](2) Complexes

The neutral rhodium(I) square-planar complexes [RhX(CO)(2)(L)] [X = Cl (3), I (4)] bearing a nitrogen-containing ligand L [diethylamine (a), triethylamine (b), imidazole (c), 1-methylimidazole (d), pyrazole (e), 1-methylpyrazole (f), 3,5-dimethylpyrazole (g)] are straightforwardly obtained from L and [Rh(μ-X)(CO)(2)](2) [X = Cl (1), I (2)] precursors. The synthesis is extended to the diethylsulfide ligand h for 3h and 4h. According to the CO stretching frequency of 3 and 4, the ranking of the electronic density on the rhodium center follows the order b > a ≈ d > c > g > f ≈ h > e. The X-ray molecular structures of 3a, 3d-3f, 4a, and 4d-4f were determined. Results from variable-temperature (1)H and (13)C{(1)H} NMR experiments suggest a fluxional associative ligand exchange for 4c-4h and a supplementary hydrogen-exchange process in 4e and 4g. The oxidative addition reaction of CH(3)I to complexes 4c-4g affords the neutral dimeric iodo-bridged acetylrhodium(III) complexes [RhI(μ-I)(COCH(3))(CO)(L)](2) (6c-6g) in very good isolated yields, whereas 4a gives a mixture of neutral 6a and dianionic [RhI(2)(μ-I)(COCH(3))(CO)][NHMeEt(2)](2) and 4h exclusively provides the analogue dianionic complex with [SMeEt(2)](+) as the counterion. X-ray molecular structures for 6d(2) and 6e reveal that the two apical CO ligands are in mutual cis positions, as are the two apical d and e ligands, whereas isomer 6d(1) is centrosymmetric. Further reactions of 6d and 6e with CO or ligand e gave quantitatively the monomeric complexes [RhI(2)(COCH(3))(CO)(2)(d)] (7d) and [RhI(2)(COCH(3))(CO)(e)(2)] (8e), respectively, as confirmed by their X-ray structures. The initial rate of CH(3)I oxidative addition to 4 as determined by IR monitoring is dependent on the nature of the nitrogen-containing ligand. For 4a and 4h, reaction rates similar to those of the well-known rhodium anionic [RhI(2)(CO)(2)](-) species are observed and are consistent with the formation of this intermediate species through methylation of the a and h ligands. The reaction rates are reduced significantly when using imidazole and pyrazole ligands and involve the direct oxidative addition of CH(3)I to the neutral complexes 4c-4g. Complexes 4c and 4d react around 5-10 times faster than 4e-4g mainly because of electronic effects. The lowest reactivity of 4f toward CH(3)I is attributed to the steric effect of the coordinated ligand, as supported by the X-ray structure.     

金属富勒烯[Dy@C_(82)(I)]膜的电化学研究

研究并对比了金属富勒烯Dy @C82 的主要异构体Dy @C82 (I)固体膜在有机溶剂乙腈及水溶液中的电化学性质 .在乙腈溶液中 ,Dy @C82 (I)膜的电化学行为不同于其溶于有机溶剂中的电化学行为 ,前两个还原峰与其对应的再氧化峰之间存在大的分裂 .但是 ,经过还原及再氧化后的Dy @C82 (I)膜却存在一对对称性很好的氧化及再还原峰 .解释为经过还原后的Dy @C82 (I)膜的结构有利于进一步氧化 ,而不需要结构重排 ;在水溶液中 ,Dy @C82 (I)膜的电化学行为不同于其在乙腈溶液中 ,却类似于其有机溶液在Pt电极上的电化学行为 ,出现了对称性很好的三对还原峰及一对氧化峰 .在水溶液中 ,Dy @ C82 (I)的前三价负离子及一价正离子是稳定的 .利用紫外 -可见 -近红外 (UV Vis NIR)光谱及扫描电镜 (SEM)等技术对膜的性质及表面形貌等进行了表征     

Copper(I) as a phosphine abstractor from (η-C5H5)(CO)(PPh3)FeCOCH3

The Cu^I complex Cu(CH₃CN)₄⁺PF₆⁻ chemoselectively abstracts phosphine from Cp(CO)(PPh₃FeCOCH₃ and produces Cp(CO)₂FeCH₃ in good yield. No evidence for electrophilic Cu^I coordinating the acetyl ligand on Cp(CO)(L)FeCOCH₃ (L = CO, PPh₃), however, was obtained Reactions of Cu^I and Cp(CO)(PPh₃)FeCH₃, with and without the presence of CO, also were examined. With CO, this methyl complex first gives its acetyl derivative Cp(CO)(PPh₃)FeCOCH₃ (1 atm CO in CH₂Cl₂ solution, 5 min), and after excess CO is removed (it otherwise blocks further reaction), Cp(CO)₂FeCH₃ forms.     

Energetics of the oxidative addition of I2 to [Ir(Μ-L)(CO)2]2 (L=S t Bu, 3,5-Me2pz,7-aza) complexes. X-ray structures of Ir(Μ-S t Bu)(I)(CO)2]2 and [Ir(Μ-3,5-Me2pz)(I)(CO)2]2

The energetics of the oxidative additive of I₂ to [Ir(-L)(CO)₂]₂ [L =t-buthylthiolate (S ^t Bu), 3,5-dimethylpyrazolate (3,5-Me₂pz), and 7-azaindolate (7-aza)] complexes was investigated by using the results of reaction-solution calorimetric measurements, X-ray structure determinations, and extended Hückel (EH) molecular orbital calculations. The addition of 1 mol of iodine to 1 mol of [Ir(-L)(CO)₂]₂, in toluene, leads to [Ir(-L)(I)(CO)₂]₂, with the formation of two Ir-I bonds and one Ir-Ir bond. The following enthalpies of reaction were obtained for this process: –125.8±4.9 kJ mol^–1 (L = S ^t Bu), –152.0±3.8 kJ mol^–1 (L=3,5-Me₂pz), and –205.9±9.9 kJ mol^⊃ (L=7-aza). These results are consistent with a possible decrease of the strain associated with the formation of three-, four-, and five-membered rings, respectively, in the corresponding products, as suggested by the results of EH calculations. The calculations also indicate a slightly stronger Ir-Ir bond for L = 3,5-Me₂pz than for L= S ^t Bu despite the fact that the Ir-Ir bond lengths are identical for both complexes. The reaction of 1 mol of [Ir(-S ^t Bu)(CO)₂]₂ with 2 mol of iodine to yield [Ir(-S ^t Bu)(I)₂(CO)₂]₂ was also studied. In this process four Ir-I bonds are formed, and from the corresponding enthalpy of reaction (–186.4±2.7 kJ mol^–1) a solution phase Ir-I mean bond dissociation enthalpy in [Ir(-S ^t Bu)(I)₂(CO)₂]₂, , was derived. This value is lower than most values reported for octahedral mononuclear Ir¹¹¹ complexes. New large-scale syntheses of the [Ir(-L)(CO)₂]₂ complexes, with yields up to 90%, using [Ir(acac)(CO)₂] as starting material, are also reported. The X-ray structures of [Ir(-L)(I)(CO)₂]₂ (L=S^tBu and 3,5-Me₂pz) complexes have been determined. For L=S^tBu the crystals are monoclinic, space group P2_l/c,a=10.741(2) å,b= 11.282(3) å,c=18.308(3) å,=96.71(1), andZ=4. Crystals of the-3,5-Me₂pz derivative are monoclinic, space group P2_l/n,a=14.002(3) å,b= 10.686(1) å,c=15.627(3) å,=112.406(8), andZ=4. In both complexes the overall structure can be described as two square-planar pyramids, one around each iridium atom, with the iodine atoms in the apical positions, and the equatorial positions occupied by two CO groups and the two sulfur atoms of the S ^t Bu ligands, or two N atoms of the pyrazolyl ligands. In the case of L=S^tBu the pyramids share a common edge defined by the two bridging sulfur atoms and for L =3,5-Me₂pz they are connected through the two N-N bonds of the pyrazolyl ligands. The complexes exhibit short Ir-Ir single bonds of 2.638(1) å for L=S^tBu and 2.637(1) å for L=3,5-Me₂Pz. The oxidative addition of iodine to [Ir(-3,5-Me₂pz)(CO)₂]₂ results in a remarkable compression of 0.608 å in the Ir-Ir separation.     

Dangling thiyl radical: stabilized in [PPh4]2[(bdt)W(VI)(O)(μ-S)2Cu(I)(SC6H4S•)

The synthesis, crystal structure, and spectroscopic characterization of [PPh(4)](2)[(bdt)W(O)(S(2))Cu(SC(6)H(4)S(?))] (3; bdt = benzenedithiolate) relevant to the active site of carbon monoxide dehydrogenase are presented. Curiously, in 3, the copper(I) benzenemonothiolate subcenter possesses a dangling thiyl radical that is stabilized by a disulfido-bridged oxo tungsten dithiolene core. The benzenedithiolate ligand, which is generally bidentate in nature, acts as a bidentate and also as a monodentate in 3. The formation of an unusual dangling thiyl radical has been magnetically and spectroscopically identified and has been supported by the density functional theory level of calculation.     

Synthesis and Crystal Structure of Bis(μ-bis(diphenyl-phosphino)methane)(μ-benzenethiolate)(acetonitrile)Dicopper(I) Perchlorate Diethylether Solvate

The reaction between [Cu2(μ-dppm)2(MeCN)4](ClO4)2(dppm=bis(diphenylphos-phino)methane) and [Zn(PhS)2(bpy)] (bpy=2,2'-bipyridine,PhS=benzenethiolate) gave the complex [Cu2(μ-dppm)2(μ-PhS)(MeCN)]ClO4·0.5(Et2O)(C58H52ClNO4P4SCu2·0.5Et2O) which was determined by X-ray single-crystal diffraction.The crystal is of orthorhombic,space group P212121 with a=13.6157(3),b=20.8022(6),c=21.3299(6)A,V=6041.4(3) A3,Mr=1182.54,Dc=1.300 g/cm3,F(000)=2444,μ=0.934 mm-1 and Z=4.The final R=0.0773 and wR=0.1843 for 7744 observed reflections (I>2σ(I)).The dicopper atoms are doubly bridged by dppm as well as one S donor from benzenethiolate.One copper atom is in a distorted trigonal bipyramidal environ- ment,whereas the other adopts a distorted tetrahedral geometry.     

Synthesis, characterization and antimicrobial studies of mixed ligand silver(I) complexes of triphenylphosphine and heterocyclic thiones: Crystal structure of bis[{(μ-diazinane-2-thione)(diazinane-2-thione)(triphenylphosphine)silver(I) nitrate}]

Mixed ligand silver(I) complexes of triphenylphosphine and heterocyclic thiones (imidazolidine-2-thione (Imt), diazinane-2-thione (Diaz) and 2-mercaptopyridine (Mpy)) having the general formulae [(Ph₃P)Ag(thione)₂]NO₃ and [(Ph₃P)₂Ag(thione)]NO₃ were prepared and characterized by elemental analysis, IR and NMR (¹H, ¹³C and ³¹P) spectroscopic methods. The crystal structure of one of the complexes, [Ag(Ph₃P)(Diaz)₂]₂(NO₃)₂ (1) was determined by X-ray crystallography. The title complex (1) is dinuclear, having each silver atom coordinated to three thione sulfur atoms of Diaz and to one phosphorus atom of PPh₃ in a nearly tetrahedral environment, with an average P-Ag-S bond angle of 108.5°. The spectral data of the complexes are consistent with sulfur coordination of the thiones to silver(I). Antimicrobial activities of the complexes were evaluated by minimum inhibitory concentrations and the results showed that the complexes exhibit a wide range of activity against two gram-negative bacteria (E. coli, P. aeruginosa) and molds (A. niger, P. citrinum), while the activities were poor against yeasts (C. albicans, S. cerevisiae).     

[Cu(L-Ile)(Phen)(H2O)(ClO4)]的合成、结构及稳定性研究

合成了三元混配配合物[Cu(L-Ile)(Phen)(H20)(ClO4)](L-Ile=L-异亮氨酸,phen=1,10-邻菲咯啉),通过红外光谱、紫外-可见光谱、摩尔电导率、X射线单晶结构分析,对配合物进行了表征.该晶体属单斜晶系,P21空间群,晶胞参数:a=1.1704(5)nm,b=0.8090(5)nm,c=2.1822(5)nm,β=98.061(5)°,Z=2,Dx=1.60Mg·m-3,R1=0.0462,wR2=0.1225.每个配合物分子中Cu(Ⅱ)离子与一个L-Ile(N,O)配体、一个Phen(N,N)配体、一个H2O(O)配体及一个ClO4-(O)形成六配位的畸变八面体构型.本文还用电位滴定法测定了配合物的稳定常数,结果表明,配合物具有高的稳定性.     

单核铜配合物[Cu~(II)(HIPP)(pydc)(H_2O)]的合成和晶体结构

用溶剂热合成方法合成了一个单核铜配合物CuII(HIPP)(pydc)(H2O),采用元素分析法和X射线单晶衍射法对该配合物的组成和结构进行了表征.配合物CuII(HIPP)(pydc)(H2O)属于正交晶系,空间群是Pbca.a=0.663 93(18)nm,b=2.062 2(6)nm,c=2.619 1(7)nm,α=90°,β=90°,γ=90°,V=3.585 9(17)nm3,Z=8,ρc=1.693g·cm-3,F(000)=1 864,GOF=0.882,R1=0.037 4,wR2=0.111 8[I2σ(I)].中心铜原子与配体脱质子2,6-吡啶二甲酸的2个羧基氧原子和1个氮原子、HIPP的1个氮原子和1个氧原子及1个水分子中的氧原子形成六配位的变形八面体.结构分析表明晶体中分子间含有氢键.     

Two heptacopper(II) disk complexes with a [Cu(7)(μ(3)-OH)(4)(μ-OR)(2)](8+) core

The reaction of CuX(2) (X(-) ≠ F(-)) salts with 1 equiv of 3-pyridyl-5-tert-butylpyrazole (HL) in basic methanol yields blue solids, from which disk complexes of the type [Cu(7)(μ(3)-OH)(4)(μ-OR)(2)(μ-L)(6)](2+) and/or the cubane [Cu(4)(μ(3)-OH)(4)(HL)(4)](4+) can be isolated by recrystallization under the appropriate conditions. Two of the disk complexes have been prepared in crystalline form: [Cu(7)(μ(3)-OH)(4)(μ-OCH(2)CF(3))(2)(μ-L)(6)][BF(4)](2) (2) and [Cu(7)(μ(3)-OH)(4)(μ-OCH(3))(2)(μ-L)(6)]Cl(2)·xCH(2)Cl(2) (3·xCH(2)Cl(2)). The molecular structures of both compounds as solvated crystals can be described as [Cu?Cu(6)(μ-OH)(4)(μ-OR)(2)(μ-L)(6)](2+) (R = CH(2)CF(3) or CH(3)) adducts. The [Cu(6)(μ-OH)(4)(μ-OR)(2)(μ-L)(6)] ring is constructed of six square-pyramidal Cu ions, linked by 1,2-pyrazolido bridges from the L(-) ligands and by basal, apical-bridging hydroxy or alkoxy groups, while the central Cu ion is bound to the four metallamacrocyclic hydroxy donors in a near-regular square-planar geometry. The L(-) ligands project above and below the metal ion core, forming two bowl-shaped cavities that are fully (R = CH(2)CF(3)) or partially (R = CH(3)) occupied by the alkoxy R substituents. Variable-temperature magnetic susceptibility measurements on 2 demonstrated antiferromagnetic interactions between the Cu ions, yielding a spin-frustrated S = (1)/(2) magnetic ground state that is fully populated below around 15 K. Electrospray ionization mass spectrometry, UV/vis/near-IR, and electron paramagnetic resonance measurements imply that the heptacopper(II) disk motif is robust in organic solvents.     

Antagonism between extreme negative linear compression and spin crossover in [Fe(dpp)(2)(NCS)(2)]⋅py

A scissor-like geometric mechanism is responsible for the strongest negative linear compression effect yet observed in a molecular material, [Fe(dpp)(2)(NCS)(2)]?py (see picture; dpp=dipyrido[3,2-a:2'3'-c]phenazine), C gray, N blue, S yellow, Fe red). The same mechanism is also responsible for suppressing the high-spin to low-spin transition under pressure.     

The formation of Pt(P–P)(X)(COAr) (X=Cl, I; Ar=Ph, 2-Tioph) complexes via insertion of carbon monoxide

Pt(diphosphine)X(aryl) complexes [diphosphine = 1,3-bis(diphenylphosphino)propane (dppp); aryl=phenyl, 2-thiophenyl; X=Cl, I] have been reacted with carbon monoxide in chloroform. It has been revealed by in situ NMR studies that the starting compounds insert carbon monoxide into the Pt-aryl group resulting in Pt(diphosphine)X{C(O)aryl} complexes. It has been found that the phenyl complexes are much more reactive than the corresponding 2-thiophenyl complexes. Similarly, higher reactivity has been observed with iodo than with the chloro complexes.     

X-ray diffraction from faulted cellulose I constructed with mixed Iα–Iβ stacking

Cellulose from higher plants is usually thought to be a composite of the Iα and Iβ allomorphs, with predominance of the latter. Instead of the pure allomorphs, this article proposes that Iα and Iβ stacking patterns coexist within each crystallite, forming a type of crystallographic defect known as stacking fault. Models of faulted crystallites are constructed with mixed Iα–Iβ stacking and their X-ray diffraction intensities are calculated using the Diffracted Intensities From Faulted Xtals (DIFFaX) computer program. Simulated powder diffractograms from faulted crystallites compare favorably with experimental data, modifying diffractogram regions that have been misfit by models based on the Iβ crystal structure. Calculations also reveal that stacking faults generate a signature in the (hkl) dependence of diffraction line broadening, guiding further experimental verification and eventual quantification of stacking faults. Our findings bring an alternative view of native cellulose polymorphism and suggest that the proposed stacking faults are ubiquitous crystallographic defects in cellulose from higher plants.     

(η-Tetraarylcyclobutadiene)(η-formylcyclopentadienyl)cobalt(I) complexes: Facilities to finetune the electron-donating capability in dipolar organometallics

Five different (η⁴-tetraarylcyclobutadiene)(η⁵-formylcyclopentadienyl)cobalt(I) complexes (1a-1e) were synthesized in reasonable yields in a one-pot reaction of CoCl(PPh₃)₃, formylcyclopentadienyl sodium and the appropriate diarylethyne. The aryl groups of the ethyne were modified by various para-substituents X (X = Cl, H, Me, OMe, NMe₂), which were intended to alter the redox potentials of the synthesized cobalt sandwich complexes. A cyclic voltammetry study revealed a linear dependence of the first oxidation potential to the Hammett parameter σ_p. X-ray structure analyses performed for two complexes (X = Me and NMe₂) demonstrate only subtle changes in the solid state structure despite the large differences in electrochemical properties. A theoretical analysis by the density functional theory method has been performed on the geometries and electronic structures of the complex (η⁴-cyclobutadiene)(η⁵-cyclopentadienyl)Co(I), its cation and dication.     

A structural and Mössbauer study of complexes with Fe(2)(micro-O(H))(2) cores: stepwise oxidation from Fe(II)(micro-OH)(2)Fe(II) through Fe(II)(micro-OH)(2)Fe(III) to Fe(III)(micro-O)(micro-OH)Fe(III)

Dinuclear non-heme iron clusters containing oxo, hydroxo, or carboxylato bridges are found in a number of enzymes involved in O(2) metabolism such as methane monooxygenase, ribonucleotide reductase, and fatty acid desaturases. Efforts to model structural and/or functional features of the protein-bound clusters have prompted the preparation and study of complexes that contain Fe(micro-O(H))(2)Fe cores. Here we report the structures and spectroscopic properties of a family of diiron complexes with the same tetradentate N4 ligand in one ligand topology, namely [(alpha-BPMCN)(2)Fe(II)(2)(micro-OH)(2)](CF(3)SO(3))(2) (1), [(alpha-BPMCN)(2)Fe(II)Fe(III)(micro-OH)(2)](CF(3)SO(3))(3) (2), and [(alpha-BPMCN)(2)Fe(III)(2)(micro-O)(micro-OH)](CF(3)SO(3))(3) (3) (BPMCN = N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)-trans-1,2-diaminocyclohexane). Stepwise one-electron oxidations of 1 to 2 and then to 3 demonstrate the versatility of the Fe(micro-O(H))(2)Fe diamond core to support a number of oxidation states with little structural rearrangement. Insight into the electronic structure of 1, 2', and 3 has been obtained from a detailed M?ssbauer investigation (2' differs from 2 in having a different complement of counterions). Mixed-valence complex 2' is ferromagnetically coupled, with J = -15 +/- 5 cm(-)(1) (H = JS(1).S(2)). For the S = (9)/(2) ground multiplet we have determined the zero-field splitting parameter, D(9/2) = -1.5 +/- 0.1 cm(-)(1), and the hyperfine parameters of the ferric and ferrous sites. For T < 12 K, the S = (9)/(2) multiplet has uncommon relaxation behavior. Thus, M(S) = -(9)/(2) <--> M(S) = +(9)/(2) ground state transition is slow while deltaM(S) = +/-1 transitions between equally signed M(S) levels are fast on the time scale of M?ssbauer spectroscopy. Below 100 K, complex 2' is trapped in the Fe(1)(III)Fe(2)(II) ground state; above this temperature, it exhibits thermally assisted electron hopping into the state Fe(1)(II)Fe(2)(III). The temperature dependence of the isomer shifts was corrected for second-order Doppler shift, obtained from the study of diferrous 1. The resultant true shifts were analyzed in a two-state hopping model. The diferric complex 3 is antiferromagnetically coupled with J = 90 +/- 15 cm(-)(1), estimated from a variable-temperature M?ssbauer analysis.     

Dynamics of electron solvation in I(-)(CH3OH)n clusters (4 ≤ n ≤ 11)

The dynamics of electron solvation following excitation of the charge-transfer-to-solvent precursor state in iodide-doped methanol clusters, I(-)(CH(3)OH)(n = 4-11), are studied with time-resolved photoelectron imaging. This excitation produces a I···(CH(3)OH)(n)(-) cluster that is unstable with respect to electron autodetachment and whose autodetachment lifetime increases monotonically from ~800 fs to 85 ps as n increases from 4 to 11. The vertical detachment energy (VDE) and width of the excited state feature in the photoelectron spectrum show complex time dependence during the lifetime of this state. The VDE decreases over the first 100-400 fs, then rises exponentially to a maximum with a ~1 ps time constant, and finally decreases by as much as 180 meV with timescales of 3-20 ps. The early dynamics are associated with electron transfer from the iodide to the methanol cluster, while the longer-time changes in VDE are attributed to solvent reordering, possibly in conjunction with ejection of neutral iodine from the cluster. Changes in the observed width of the spectrum largely follow those of the VDEs; the dynamics of both are attributed to the major rearrangement of the solvent cluster during relaxation. The relaxation dynamics are interpreted as a reorientation of at least one methanol molecule and the disruption and formation of the solvent network in order to accommodate the excess charge.     

Synthesis and Characterization of Nitrato-Triamine-Metal(II) Complexes. Conglomerate Crystallization Part 55. Crystal Structure of [Ni(dien)(O2NO)(ONO2)] (I), {[Cu(dien)-(μ-ONO2)]NO3}∞ (II), [Zn(dien)(O2NO)(ONO2)] (III), [Ni(Medpt)(O2NO)(ONO2)] (IV) and [Cu(Medpt)(ONO2)2] (V)

In absolute ethanol and in the presence of triethylorthoformate, reactions of metal(II) nitrates with linear tridentate amines afforded metal complexes of the formula M(NNN)(NO₃)₂, where M = Ni²⁺, Cu²⁺ and Zn²⁺, and NNN = dien and Medpt. The compounds fall into three categories in accordance with their stereochemistry and mode of binding of the nitrato ligands. Compounds I, [Ni(dien)(O₂NO)(ONO₂)] and III, [Zn(dien)(O₂NO)(ONO₂)] are isomorphous and isostructural. They crystallize in the monoclinic space group P2₁/n with nearly identical cell constants. The stereochemistry of these two compounds is such that the terdentate dien ligand forms a fac MN₃ moiety with the two oxygens of the bidentate nitrato ligand trans to the terminal NH₂. These ligands form the base of the octahedral arrangement in which the sixth position, trans to the secondary nitrogen of the dien, is an oxygen of the monodentate nitrato ligand. Compound IV, [Ni(Medpt)(O₂NO)(ONO₂)] falls into the same category as I and III despite the fact that the two rings in the Ni-Medpt moiety are six-membered rings, unlike those in compounds I and III which are five-membered rings. Nevertheless, the nickel-amine arrangement is fac. The bidentate nitrato-oxygens are trans to the terminal NH₂ of the amine ligand, and the oxygen of the monodentate nitrato ligand is trans to the tertiary amine-nitrogen. Such stereochemistry is prevalent for nickel and zinc compounds. Interestingly, compound IV crystallizes as a conglomerate (space group P2₁2₁2₁). Compound II, {[Cu(dien)(μ-ONO₂)]NO₃}_∞ belongs to the second category and has a polymeric structure. The repeating fragment in the polymeric chain is a Cu(dien)-O fragment with the monodentate nitrato ligand occupying an equatorial position of the base. A second oxygen of the equatorial nitrate becomes an axial ligand for an adjacent Cu-N₃O fragment. In this way the substance propagates into an infinite chain. The repeating unit has an effective square pyramidal, five-coordinate, configuration. Finally, the compound crystallizes as a racemate. The second nitrate necessary for charge compensation of this copper(II) compound is ionic and its function is to hold the infinite chains of the lattice. The third category represented by compound V, [Cu(Medpt)(ONO₂)₂] contains two molecules in the asymmetric unit of the racemic lattice (monoclinic, space group P2₁/a). The structure of Cu-Medpt is unlike that of IV in that both species present in the asymmetric unit have the amine ligand in a mer configuration which together with a monodentate oxygen of a nitrato ligand form a base plane of a square pyramid. The fifth ligand of both Cu²⁺ ions is a second monodentate nitrato ligand. The stereochemical differences between the two Cu²⁺ ions are insignificant for the Cu-Medpt fragment, which share the same conformation and configuration. The major difference between the two species is the torsional angles defined by the Cu-O-N-O angles. The difference arises from variation in the hydrogens of the primary amine moieties selected by nitrato-oxygens to form intramolecular hydrogen bonds. Finally, there is a little variation in the equatorial Cu-ONO₂ stereochemistry because of steric hindrance, imposed by the Medpt, preventing large torsional angles by these nitrato ligands. This is evident by comparing the two copper species shown in Finally, nitrate-to-Br ligand exchange was found to take place when KBr pellets are prepared for IR spectral measurements.     

cis-[Pt(depe)(NCS)(SCN))]和cis-[Pt(dPr'pe)(NCS)]配合物的合成和分子结构

本文研究了在1:1丙酮-水混合溶剂中回流条件下, cis-[Pt(diphos)Cl2]与NaCNS之间的取代反应, 第一次合成了CNS的混合键合异构体的depe铂配合物cis-[Pt(depe)(NCS)(SCN)], 进行了分子结构测定, 属单斜晶系, 空间群为P21/n晶胞参数: a=7.296(5), b=14.434(4), c=18.042(4)A, β=95.72(8)°,V=1890.7A^, Z=4, Rf=0.0564, 在相同条件下用dPr'pe作了对照实验, 得到的是cis-[Pt(dPr'pe)(NCS)2], 属单斜晶系, 空间群为Cc, 晶胞参数, a=12.279(6),b=9.330(8), c=20.102(7)A, β=108.90(9), V=2179.0(3)A^3, Z=4,Rf=0.0419. 此外, 还从双膦烷基的空间效应和电子效应讨论了对取代反应产物的影响。     

cis-[Pt(depe)(NCS)(SCN))]和cis-[Pt(dPr'pe)(NCS)]配合物的合成和分子结构

本文研究了在1:1丙酮-水混合溶剂中回流条件下, cis-[Pt(diphos)Cl2]与NaCNS之间的取代反应, 第一次合成了CNS的混合键合异构体的depe铂配合物cis-[Pt(depe)(NCS)(SCN)], 进行了分子结构测定, 属单斜晶系, 空间群为P21/n晶胞参数: a=7.296(5), b=14.434(4), c=18.042(4)A, β=95.72(8)°,V=1890.7A^, Z=4, Rf=0.0564, 在相同条件下用dPr'pe作了对照实验, 得到的是cis-[Pt(dPr'pe)(NCS)2], 属单斜晶系, 空间群为Cc, 晶胞参数, a=12.279(6),b=9.330(8), c=20.102(7)A, β=108.90(9), V=2179.0(3)A^3, Z=4,Rf=0.0419. 此外, 还从双膦烷基的空间效应和电子效应讨论了对取代反应产物的影响。