The phenomenon of conglomerate crystallization: XXXVII: The crystallization behavior of the Cr(III) and Co(III) amine carbonates [Cr(en)2CO3]I (I) and NH4{[cis-β-Co(trien)Co3]2}(PF6)3 (II)

[Cr(en)₂CO₃]I (I), ICoO₃N₄C₅H₁₆, crystallizes from water at 21°C in space groupP2₁/c (no. 14), with lattice constantsa=7.298(4),b=8.622(8),c=17.577(6)Å,=91.29(4)°;V=1105.59 ų andd(calc; MW=359.11, Z=4)=2.157 g cm^–3. A total of 2825 data points were collected over the range of 4°250°; of these, 1855 (independent and withI3(I)) were used in the structural analysis. Data were corrected for absorption (=37.657 cm^–1) and the transmission coefficients ranged from 0.4850 to 0.9991. The finalR(F) andR _w(F) residuals were, respectively 0.134 and 0.113. The cations exist in the lattice as the enantiomeric pair () and (). NH₄{[cis--Co(trien)CO₃]₂}(PF₆)₃ (II), Co₂P₃F₁₈O₆N₉C₁₄H₄₀, crystallizes from water at 21 °C in space groupP2₁/c (no. 14), with lattice constantsa=10.397(2),b=20.292(3),c= 27.082(4) Å,=100.30(3)°;V=3545.70 ų andd(calc; MW=983.29, Z=4)=1.842 g cm^–3. A total of 3724 data were collected over the range of 4°250°; of these, 2653 (independent and withI3(I)) were used in the structural analysis. Data were corrected for absorption (=12.031 cm^–1) and the transmission coefficients ranged from 0.8326 to 0.99985. The finalR(F) andR _w (F) residuals were, respectively 0.104 and 0.124. The cations exist in the asymmetric unit as() and()[cis--Co(trien)CO₃]⁺ pairs. The three independent PF₆ ^– anions exhibit the usual high thermal motion typical of these species and the NH₄ ⁺ cation is either disordered or exhibits high thermal motion also (its H atoms could not be found in difference maps).     

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.     

The infra-red spectrum of [Co(en)3]Cl3·3T2O (en: ethylenediamine)

The infra-red spectrum of [Co(en)₃]Cl₃·3T₂O has been observed over a period of 5 months. The spectrum changes considerably even in 2 days after preparation of the hydrate, revealing quite different features from the parent. Initially some bands due to the NH₂ group disappear, while new bands appear. These are explained in terms of a change in bonding character or as an interaction between the complex ion and the chloride anion in the crystal. Subsequently, the bands due to ethylenediamine decrease in intensity and almost vanish, while additional new bands appear. The new bands are explained in terms of ammine complexes. It is proposed that a decomposition reaction of en → 2NH₃ + HCCH takes place through intermediates such as vinylamine and so on. After one month the spectrum still changes slowly with further new bands due to a HT exchange reaction.     

THE PHENOMENON OF KRYPTORACEMIC CRYSTALLIZATION. PART 1. COUNTERION CONTROL OF CRYSTALLIZATION PATHWAY SELECTION. PART 4. THE CRYSTALLIZATION BEHAVIOR OF (+/−)-[Co(tren)(NO2)2]Br(I), (+/−)-[Co(tren)(NO2)2]2Br(ClO4) · H2O(II), (+/(−)-[Co(tren)(NO2)2]ClO4(III) AND ATTEMPTS TO SOLVE THE STRUCTURE OF (+/−)-[Co(tren)(NO2)2]NO3(IV)

Abstract

Racemic aqueous solutions of (+/?)-[Co(tren)(NO₂)₂]Br (I), (+/?)-[Co(tren)(NO₂)₂]ClO₄ (III) and [Co(tren)(NO₂)₂]NO₃(IV) crystallize as racemates. By contrast, the double salt, (+/?)-[Co(tren)(NO₂)₂]₂Br(ClO₄) · H₂O(II), produces kryptoracemic crystals belonging to the enantiomorphic space group P2₁2₁2₁ (No. 19). The former three species crystallize with one molecule in the asymmetric unit; in the latter, a racemic pair is the asymmetric unit, a fact which is hidden by the enantiomorphic nature of its space group – thus the name of the crystallization phenomenon reported. In (II) pairs of cations are related by an approximate, non-crystallographic, inversion center. The crystal structure and polarity of (I) and the absolute configuration of (II) were determined by refinement. The crystalline contents of (I) to (III) consist of infinite strings of hydrogen bonded cations, the counter ions and (where relevant) waters of crystallization acting as a hydrogen-bonding glue linking the spiral strings

In (II), the N-CH₂-CH₂-NH₂-Co rings of Co(1) are (δδλ) and those of Co(2) are (λλδ) and adjacent strings are linked by the counter-anions and the water of crystallization. Pairs of Co(1) and of Co(2) cations are hydrogen bonded to one another by two N-O···H-N linkages. Finally, pairs of composition Co(1)-Co(1) as well as of Co(2)-Co(2) share another pseudo-inversion center which is approximately valid for the CoN₆ portion of each cation. Since the atoms of the cation are ordered, it is impossible for the pseudo-inversion center to be valid for the -CH₂-CH₂- fragment of the Co(1)-Co(1) or of Co(2)-Co(2) pairs. (I) and (III) crystallizes as racemates whose five-membered rings have chiroptical symbols (δδλ), or its enantiomer.     

The phenomenon of conglomerate crystallization in coordination compounds. XXIII: The crystallization behavior of [cis-Co(en)2(N3)(SO3)] · 2H2O (I) and of [cis-Co(en)2(NO2)(SO3)] · H2O (II)

A room temperature water solution of (I) crystallizes as a racemate, space groupP2 ₁/n with lattice constantsa=7.737(6),b=10.694(5),c=15.097(6) Å, and=102.83(5)°;V=1218.05 ų andd (calc; M.W.=337.24, Z=4) = 1.642 g cm^–3. A total of 2381 data were collected over the range 4° 2 < 50°; of these, 1452 (independent and withI 3(I)) were used in the structural analysis. Data were corrected for absorption ( = 15.76 cm^–1), and the relative transmission coefficients ranged from 0.8976 to 0.9984. Refinement led to the finalR(F) andR _w(F) residuals of 0.0858 and 0.1116. A room temperature water solution of (II) crystallizes as a racemate in space group P2₁/c with lattice constantsa=6.638(3),b=11.425(8),c=15.147(16) Å, and=93.27(6)°; F=1146.8 Å andd (calc; M.W.=323.2,Z=4) = 1.872 g cm^–3. A total of 2200 data were collected over the range 4° 2 < 50°; of these, 1918 (independent and withI 3(I)) were used in the structural analysis. Data were corrected for absorption (=16.94 cm^–1), and the relative transmission coefficients ranged from 0.9049 to 0.9967. Refinement led to the finalR(F) andR _w(F) residuals of 0.0231 and 0.0279. The chirality symbol for the particular enantiomer of (I) refined here is (), while for (II) the chirality symbol is (), which means that in the latter compound one of the en rings is in a higher energy conformation. We attribute this result to competitive intramolecular hydrogen-bonded interactions between the — NH₂ hydrogens of the en ligands and the oxygens of the -NO₂ and -SO₃ ligands, strengths which are enhanced by coercing a change in sign of the torsional angle of one en ringa motion which permits both oxo ligands to form stronger hydrogen bonds while retaining proper O O contacts. This phenomenon is not observed in (I) since the azide ligand does not compete with -SO₃ for such hydrogen-bonded interactions, and nonbonded pair repulsions can be minimized without affecting the ability of — SO₃ oxygens to form strong intramolecular hydrogen bonds.     

[Cr(III)(4-ASA)(en)2]Cl配合物的光化学活性

通过吸收光谱、荧光光谱、电导率和ESI-MS质谱等方法讨论了铬配合物[Cr(III)(4-ASA)(en)2]Cl (4-ASA: 4-aminosalicylic acid dianion, en: ethylenediamine)在不同温度、不同pH溶液中的稳定性及光化学稳定性. 实验表明, 该配合物的溶液(pH 7.4)在日光照射下发生了光化学取代反应, 取代产物为[Cr(4-ASA)(en)(H2O)2]＋. 同时研究了配合物及其光照产物对EDTA的动力学反应和对DNA的切割反应. 琼脂糖凝胶电泳实验表明, 配合物的光化学产物[Cr(4-ASA)(en)(H2O)2]＋能有效切割pBR 322 DNA.     

The unusual stability of [NpO2Cl4]2−: Synthesis and characterisation of [NpO2(DPPMO2)2Cl]2[NpO2Cl4] and [Ph3PNH2]2[NpO2Cl4]

The [NpO₂(DPPMO₂)₂Cl][NpO₂Cl₄] complex (where DPPMO₂ = bis(diphenylphosphino)methanedioxide) contains the linear neptunyl group, {NpO₂}²⁺, with two bidentate P=O donor ligands. Coordinating anion Cl^? fills the fifth equatorial coordination site yielding a complex of general formula [NpO₂(DPPMO₂)₂X]₂[Y] (1) (where X = Cl^? and Y = [NpO₂Cl₄]^2?. Reaction between our newly prepared neptunium starting material [NpO₂Cl₂(thf)]_n and phosphinimine ligand produced crystals of [Ph₃PNH₂]₂[NpO₂Cl₄] (2). Compounds 1 and 2 have been structurally characterised.     

THE CRYSTALLIZATION BEHAVIOR OF [cis-α-Co(trien)(OX)lCl 2H2O (I), [cis-α-Co(trien)(NO2)2]BF4 (II), [cis-α-Co(trien)(NO2)2]-(cis-α-Co(trien)(OX)]Cl l/2SiF6 (III)

Abstract

Three new compounds were synthesized and their crystal structures determined. For compound (I). [cis-α-Co(trien)(OX)]Cl 2H₂O, CoClO₆N₄C₈H₂₂, triclinic, space group P-l (No. 2) a = 6.980(5), b = 8.801(4), c = 12.554(8) Å, α = 89.07(5)°, ? = 75.74(4)°, γ = 81.44(5)°, V = 738.9(8) ų, cell dimensions were obtained from 24 reflections giving FW = 364.4, Z = 2, F[000) = 380.06, Dcalc=1.634mg m-³, μ = 1.36mm-¹. A total of 1907 data were collected over the range of 4° ≤ 2θ ≤ 45°; of these, 1647 (independent and I≥3σ(I)) were used in the structure analysis. Data were corrected for absorption; transmission coefficients ranged from 0.51754 to 0.73648. The final RF and Rw residuals were 0.033 and 0.042.

For compound (II), [cis-α-Co(trien)(NO₂)₂]BF₄, CoN₆C₆O₄BF₄H₁₈, orthorhombic space group Pbca (No. 61) α= 12.260(10), b=12.880(14), c= 17.940(14)A F=2833(4)A³, cell dimensions were obtained from 24 reflections with 2θ in the range of 4.00–45.00 degrees, FW = 383.98, Z = 8, F(000) = 1571.52, Dcalc= 1.801 mgirT³, μ=1.28mm^_1, λ = 0.70930 Å. A total of 1637 data were collected over the range of 4° ≤ 2θ ≤ 45°; of these, 883 (independent and I≥ 2.5σ(I)) were used in the structure analysis. The final RF and Rw residuals were 0.122 and 0.132.

For compound (III), [cis-α-Co(trien)(OX)][cis-α-Co(trien)(NO₂)₂]Cl-l/2SiF₆, Co₂ClSi-l/2N₁₀C₁₄F₃O₁₂H₃₆, orthorhombic, space group Pbca (No. 61) a = 12.804(10), b= 16.543(10), c = 27.419(23) A, V= 5808(7) ų, cell dimensions were obtained from 25 reflections, FW = 760.85, Z = 8, F(000) = 3136.06, Dcalc= 1.740mg m^?3, 4mU= 1.34 mm-¹, λ = 0.70930 Å. A total of 2657 data were collected over the range of 4° ≤ 2θ ≤ 40°; of these, 1902 (independent and I≥ 2.5σ(I)) were used in the structure analysis. The final RF and Rw residuals were 0.058 and 0.062.     

关于[Co(NH3)5NO2]Cl2键合异构体相互转化的研究

[Co(NH_3)_5NO_2]Cl_2是最早发现和首先分离得到的第一个键合异构体。长期被认为只有氧配位的[Co(NH_3)_5ONO]Cl_2异构体会向氮配位的[Co(NH_3)_5NO_2]Cl_2异构体转化。本文认为氮配位的异构体也会向氧配位的异构体转化,并测定和报导了这种转化的速率常数。     

为什么[Co(NH3)5Cl]2+与[Co(NH3)6]3+的颜色不同?

结合对［Ｃｏ（ＮＨ３）５Ｃｌ］＾２）与［Ｃｏ（ＮＨ３）６］＾３＋的颜色的比较，阐述配体场理论中有关电子组态、能级、轨道、配体场谱项及谱项间跃迁等基本概念及难点。即使不做严格的量子化学计算，从直观的物理模型、简单的分子轨道理论、群论方法及有关谱图中也能获得有用信息。     

Trimercurated acetaldehyde. The crystal structures of 2[OHg3CCHO]NO3 · HNO3 and [HOHg2(NO3Hg)CCHO]NO3

Three new compounds 2[OHg₃CCHO]NO₃ · HNO₃ (A), [HOHg₂(NO₃Hg)CCHO]NO₃ (B) and (NO₃Hg)₃CCHO (C), have been successively obtained by mercuration of acetaldehyde with mercuric nitrate containing increasing concentrations of nitric acid. All of them contain trimercurated acetaldehyde. The orthorhombic crystals of A built up of parallel infinite networks of the polymeric trimercurated oxonium [OHg₃CCHO]_nⁿ⁺ cation, while the monoclinic crystals of B contain polymeric dimercurated oxonium [HoHg₂(NO₃Hg)CCHO]_nⁿ⁺¹ cation in the form of an infinite helical chain. The structures were determined by X-ray diffraction and refined by full-matrix least-squares to the R value of 0.050 for A and 0.063 for B. The Hg-C and Hg-O distances are in the ranges 2.04 to 2.11 Å and 2.11 to 2.18 Å, respectively. The crystals of C were not suitable for X-ray structure analysis.     

Crystal structures of [Pd(NH3)3(NO2)][Rh(NH3)2(NO2)4] and [PdEn2][Rh(NH3)(NO2)5]·0.75H2O

The structure of double complex salts [Pd(NH₃)₃(NO₂)][Rh(NH₃)₂(NO₂)₄] and [PdEn₂][Rh(NH₃)(NO₂)₅]·0.75H₂O is determined by single crystal X-ray diffraction. In the structures, the main structural moieties are identified.     

Trimercurated acetic acid. The crystal structures of [Hg(H2OHg)(NO3Hg)CCOO]NO3 and 2(NO3Hg)3CCOOH·HNO3

Two nitrates of trimercurated acetic acid, obtained from the solution of mercuretin in nitric acid, were identified as [Hg(H₂OHg)(NO₃Hg)CCOO]NO₃ (A) and 2(NO₃Hg)₃CCOOH·HNO₃ (B) by X-ray diffraction. The cation of A is an infinite chain composed of the -Hg(H₂OHg)(NO₃Hg)CCOO- units joined through the CHgO linkages with mean bond lengths of 2.08(3) (CHg) and 2.11(3) Å (HgO). The chains are connected by hydrogen bonding between the water molecule and the carboxyl oxygen with OH⋯O distances of 2.61(4) Å. The structure of B consists of discrete molecules of (NO₃Hg)₃CCOOH. One half of the molecules in the unit cell join up to give centrosymmetrical pairs through the carboxyl groups, with OH⋯O bonds of 2.61(7) Å, and the other half are hydrogen-bonded to the nitric acid via the carboxyl group, with an O⋯O distance of 2.59(8) Å.     

Comparative study of crystal structures of [M(NH3)5NO2]XY and [M(NH3)5ONO]XY. Crystal structure of [Co(NH3)5NO2](NO3)2·0.25H2O

The crystal structure of [Co(NH₃)₅NO₂](NO₃)₂·0.25H₂O has been determined. Co₁N₈O_8.25H_15.5, a=7.582(3), c=10.331(3) Å, V=593.9(5) ų, d_calc=1.782 g/cm³ for Z=2, space group I 4mm (C _4v ⁹ , No. 107). The structure is of the island type. Complex (distorted octahedral) cations are bonded to the NO ₃ ^? anions by electrostatic forces. Crystallization water is located in the vicinity of the labile NO₂ group.     

Synthesis and Crystal Structure of [Pd(NH_3)_4]Cl_2·2[Pd(NH_3)_3Cl]Cl

PreparahonofsomecomplexcomPOundsof[Pd(NH3)41X2tw,tvhereX=Cl-,Br,I-,X2=Co,:-,RdChl'-,etc.,wasdescribedasearlyl942l'].SynthesisandcryStalstIUCtUreOfthesaltSt'ithamons,Cr2o7",Cro.:',MoO"',andC,o'=',ttcrestillreportedmorcrecenh/'-'j.IPd(NH)4lX2,tvhereX=Cl',BrandNOz,isanotherkindofamndnepalladiumcomplexcompounds.IntheSyStemofIPd(NH).1"-Cl'-H2o,diamlltinedichloridepalladium(II)wasObtalnedbythereachonOfIPd(NH)4lHcomplexionwtthanutebydrogenchloride,andtetrachloridepalladiumaDbythe…     

THE PHENOMENON OF CONGLOMERATE CRYSTALLIZATION. PART 50. THE CRYSTALLIZATION BEHAVIOR OF [trans-Co(en)2(NO2)2]ClO4 (I), MESO-[Co-trans-Me-(N-Me-ETHYLENEDIAMINE)2-trans-(NO2)2]ClO4 (II), K[trans-Co(β-ALANINATO)2(NO2)2] (III) AND THE ISOLATION AND PARTIAL STRUCTURAL DESCRIPTION OF (H5O2)[trans-Co(β-ALANINATO)2(NO2)2] (IV)

Abstract

[trans-Co(en)₂(NO₂)₂]ClO₄ (I) crystallizes, at 22°C, from a deionized water solution, as a racemate, in space group P$1 (No. 2), with lattice constants: a = 6.581(2)Å, b = 8.274(1) Å, c = 12.660(3)Å, α = 77.28(2)Å, β = 76.58(2)°, γ = 75.20(2)° V = 638.71;ų and d(calc; MW = 370.59,z = 2) = 1.927gcm^?3. A total of 2233 data were collected over the range of 4° ≤ 2θ ≤ 50° of these, 1961 (independent and with I ≤ 3σ(I)) were used in the structural analysis. Data were corrected for absorption (μ = 15.989 cm^?1) and the relative transmission coefficients ranged from 0.6792 to 0.9874. The final R(F) and R≤(F) residuals were, respectively, 0.0738 and 0.0763. Two half cations are located at inversion centers; the anions are in general positions.

meso-[Co-trans-Me-(N-Me-ethylenediamine)₂-trans(NO₂)₂]ClO₄ (II) [(N-Meen) = N-methyl-ethylenediamine] crystallizes at 22°C, from a deionized water solution in space group Pbca (No. 61) with lattice constants: a = 16.882(5) Å, b = 11.990(3) Å, c = 15.017(5) Å; V = 3039.72 ų and d (calc;MW = 398.64, z = 8) = 1.742g cm^?3. A total of 5281 data were collected over the range of 4° ≤ 2θ ≤ 50° of these, 1779 (independent and with I ≤ 2.5σ(I) were used in the structural analysis. Data were corrected for absorption (μ = 13.501 cm^?1 and the transmission coefficients ranged from 0.7956 to 0.9947. The final refinement of the structure (anisotropic thermal parameters for the heavy atoms; idealized hydrogens for the cation) are R(F) = 0.045 and R_w (F) = 0.052). The -NO₂ ligands are trans to one another in the axial direction while the N-methyl groups are trans to one another across the basal plane. The cations are located in general positions and the torsional angles of the en rings are δ(N1-C1-C2-N2 = 52.0°) and δ(N3-C3-C4-C4 = 51.0°), in contrast with those of (I) which are of opposite helical chirality. This compound is one of two trans-Co(III)X₂ cations of which we are aware that, while sitting at a general position of the space group, has two ethytenediamine rings of the same helical chirality.

K[trans-Co(β-alaninato)₂(NO₂)₂] (III) obtained after several batches of crystals of (TV) had separated from the mother liquor (see Syntheses). (III) crystallizes at 22°C, in space group Cc (No. 9) with lattice constants: a = 12.385(6)Å, b=13.109(5)Å, c = 8.290(5)Å, β=115.19° V = 1217.97 ų and d(calc; MW = 366.22, z = 4) = 1.997 g cm^?3. A total of 1238 data were collected over the range of 4° ≤ 2θ 50° of these, 1016 (independent and with I ≤ 2.5σ(I) were used in the structural analysis. Data were corrected for absorption (μ 17.90cm^?1) and the transmission coefficients ranged from 0.5322 to 0.6627. The final R(F) and R_w (F) residuals were, respectively 0.020 and 0.022. Solution of the structure, using the first batch of crystals, proved that the compound isolated was the (H₅O₂)⁺ derivative (see below and Discussion). A later batch of crystals contained (III). We have previously observed the precipitation of hydronium salts, trapped by amine carboxylato salts of cobalt (see Discussion). The anions consist of two six-membered rings formed by the metal and two (O,N)-bound β-alaninato ligands; and, both have chair conformations.

(H₅O₂) [trans-Co(β-alaninato)₂(NO₂)₂] (IV) is the substance that first crystalized from an aqueous solution of (III) (see Experimental). It crystallizes, at 22°C, in space group Cc (No. 9) or C2/c (No. 15) with lattice constants: a=12.389(39)Å, b=13.120(11)Å, c=8.299(9) Å, β=115.09(19)° V=1221.72 ų and d(calc; MW=364.15, z=4) = 1.980 g cm^?3. An incomplete data set of 1592 reflections was collected over the range 4° ≤ 2θ ≤ 50° because the crystal decomposes in air due to rapid loss of water of crystallization, as shown by differential scanning calorimetry. 956 data were independent with I ≤ 2.5°(I) and were used in the structural analysis. Data were not corrected for absorption because of decomposition of the crystal. The final R(F) and R_w (F) residuals were, respectively, 0.14 and 0.16. To the precision of such a data set, the anions are identical with those found in (III); however the cation, which sits at an inversion center, consists of a proton sandwiched between the oxygens of two waters thus forming (H₅O₂)⁺ cations similar to those we have described in the past (see Refs. [15–18]).     

The reaction of [Ru(bpy)2(NO)Cl]2+ and [Fe(CN)5NO]2− with benzylamine: coordinated nitrosyl as an oxidizing agent

[Fe(CN)₅NO]^2–, (1) and [Ru(bpy)₂(NO)Cl]²⁺, (2) react with PhCH₂NH₂ to produce mainly N-benzylphenyl-methanimine and PhCN as oxidation products. (PhCH₂)₂NH, PhCH₂Cl and PhCH₂OH are formed as diazotization products. Products derived from the benzyl radical (such as PhMe), are also formed. Since oxidation products are generated even in the absence of oxygen, a mechanism in which the nitrosyl ligand acts as an oxidant is proposed.     

Synthesis and Crystal Structure of a Novel Co(Ⅱ)-Nitronyl Nitroxide Complex [Co(IM2-Py)(PCA)(N3)2]

The title compound [Co(IM2-Py)(PCA)(N3)2] (IM2-Py = 2-(2'-pyridyl)-4,4,5,5-te- tramethylimidazoline-1-oxyl, PCA = 2-pyridine carboxylic acid) has been prepared and structurally characterized by elemental analysis, IR spectra and X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 13.169(3), b = 11.235(2), c = 15.596(3) (A), β = 104.70(3)°, V = 2232.0(8) (A)3, C18H21CoN1oO3, Mr = 484.38, Z = 4, Dc = 1.441 g/cm3,μ(MoKα) = 0.811 mm-1, F(000) = 1000,the final R = 0.0563 and wR = 0.1010. The nitronyl nitroxide (NIT2Py) was reduced to IM2-Py, and another NIT2Py oxidated to PCA. The self-redox reaction between the radicals was observed. The cobalt(Ⅱ) ion is six-coordinated into a distorted octahedral geometry. Meanwhile, the intermolecular hydrogen bonds result in the dimer.     

Synthesis and Crystal Structure of a Novel Co(II)-Nitronyl Complex [Co(IM2-Py)(PCA)(N_3)_2]

1 INTRODUCTION The design and synthesis of molecule-based mag-netic materials is one of the major subjects of mate-rials science. Nitronyl nitroxides acting as useful pa-ramagnetic building blocks have been extensively usedto assemble molecular magnetic materials in the pastfew years[1～5]. However, their weakly basic charac-ter strongly limits their coordination ability. Mean-while, the azide anion is a versatile ligand which canlink the transition metal atoms with different coor-dinatio…     

The synthesis and crystal structure of novel Mo-Sn tetranuclear cubane-like cluster [Mo3(SnBr3)(μ3-O)(μ3-S)3(dtp)3(py)3]·(CH2Cl2)

The synthesis and crystal structure of the first example for hybrid Sn-Mo tetranuclear cubane-like cluster compound containing S/O mixed triple capping atom [Mo₃(SnBr₃)(μ ₃-O)(μ ₃-S)₃(dtp)₃(py)₃]·(CH₂Cl₂) (A) (dtp=S₂P(OC₂H₅)₂) are reported. The compound is prepared by the reaction of [Mo₃(μ ₃-O)(μ-S)₃(dtp)₄·(H₂O)] with SnBr ₃ ^? . The molecular structure of the cluster can be described as a [Mo₃OS₃] core with the SnBr ₃ ^? fragment linked to {Mo₃} triangle by three (μ ₃-S). Three Mo-Mo bond lengths are 2.616(2), 2.620(2), 2.628(2) Å, respectively, and the molecule has approximately C_3v symmetry. There is no bonding between Sn and Mo atoms, however, the addition of SnBr ₃ ^? may cause electron transfer from Sn²⁺ to [Mo₃OS₃] core to result in the shortening of Mo-Mo bond distances. The compound crystallizes in the monoclinic space group P2₁/n with refined lattice parameters ofa=13.012(4),b=22.877(6),c=18.585(6) Å,β=96.34(3)°,V=5498(3)ų, andZ=4. Full matrix refinement converged with final agreement factor ofR=0.054,R _w=0.064.