Gas-phase electronic absorption spectroscopy of substituted bis(η<Superscript>6</Superscript>-benzene)chromium derivatives: Rydberg transitions in bis(η<Superscript>6</Superscript>-anisole)chromium and bis(η<Superscript>6</Superscript>-2,6-dimethylpyridine)chromium

Gas-phase electronic absorption spectra of chromium bisarene complexes with oxygen- and nitrogen-containing ligands, (⁶-PhOMe)₂Cr (1) and (⁶-2,6-Me₂C₅H₃N)₂Cr (2), were first measured. Rydberg bands disappearing on going to the condensed-phase spectra were revealed. The first ionization potentials of complexes 1 and 2 (5.30 and 5.40 eV, respectively) were determined from the Rydberg frequencies. The Rydberg transitions were assigned and the corresponding Rydberg term values and quantum defects were determined. The effect of heteroatoms on the Rydberg structure parameters was revealed by comparing the spectra of complexes 1 and 2 with those of unsubstituted analogs. The appearance, in the ligand side chain, of an oxygen atom capable of being involved in conjugation with the -electron system of the aromatic ring results in substantial broadening of the observed Rydberg bands. This can be associated with an increased ligand contribution to the HOMO of the sandwich compound. The influence of the oxygen atom on the ionization energy of the molecule is insignificant. In contrast to this, introduction of a nitrogen atom into the carbocycle leads to a noticeable increase in the ionization potential of the molecule, while the ligand contribution to the HOMO of the complex remains practically unchanged.Based on materials of a lecture presented at the International Conference Modern Trends in Organoelement and Polymer Chemistry dedicated to the 50th anniversary of the A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences (Moscow, May 30–June 4, 2004).Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1854–1859, September, 2004.     

Synthesis and structure of novel coordination compounds based on [Re<Subscript>6</Subscript>Q<Subscript>8</Subscript>(CN)<Subscript>6</Subscript>]<Superscript>4–</Superscript> (Q = S,Se) and (SnMe<Subscript>3</Subscript>)<Superscript>+</Superscript>

The reactions of SnMe₃Cl with salts of the cluster anionic complexes [Re₆Q₈(CN)₆]^4? (Q = S, Se) gave novel complexes [{(SnMe₃)₂(OH)}₂{SnMe₃}₂{Re₆S₈(CN)₆}] (I), (Me₄N)₂[{SnMe₃(H₂O)}₂{Re₆Se₈(CN)₆}] (II), [{(SnMe₂)₄(μ₃-O)}₂{Re₆Se₈(CN)₆}] (III), and [(SnMe₂)₄(μ₃-O)₂(μ₂-OH)₂(H₂O)₂][{SnMe_{3 2}{Re₆Se₈(CN)₆}] (IV). The structures of I–IV were determined by X-ray diffraction. Compounds I, IV have the chain structures with the CN-SnMe₃-NC bridges between the cluster anions [Re₆Q₈(CN)₆]^4?. Compound II contains isolated fragments {SnMe₃(H₂O)}₂{Re₆Se₈(CN)₆}^2?. In the polymer framework of compound III, the cluster anionic complexes [Re₆Se₈(CN)₆]^4? are bound by the complex cations [(SnMe₂)₄(μ₃-O)₂]⁴⁺ formed due to the hydrolysis of the initial (SnMe₃)Cl.     

Nickel(II) tetraaqua bis(benzoate) tris(phenylacethydrazide) complex [Ni(HL<Superscript>1</Superscript>)<Subscript>3</Subscript>](L<Superscript>2</Superscript>)<Subscript>2</Subscript> · 4H<Subscript>2</Subscript>O: Synthesis and crystal and molecular structure

The synthesis, IR and Raman spectroscopic study, and X-ray diffraction analysis of [Ni(HL¹)₃](L²)₂ · 4H₂O (I), where HL¹ is phenylacetic acid hydrazide and L² is the benzoate monoanion, have been performed. The structural units of a crystal of complex I are complex [Ni(HL¹)₃]²⁺ cations, (L²)^– anions, and crystallization water molecules. The nickel atom is coordinated to the three oxygen atoms at octahedron apices and the three nitrogen atoms of three bidentate chelate (О, N) ligands HL¹ in cis,trans-meredianal (fac) conformation. The structural units of a crystal of complex I are bonded by a branched network of О–Н···О and N–H···O hydrogen bonds.     

Synthesis of substituted 1-thia-3-aza-λ<Superscript>5</Superscript>-phosphacyclohex-2-ene

The addition of dimethylamine to O-phenyl 2-chloropropylisothiocyanatophosphonate afforded the six-membered cyclic product, viz., 1-thia-3-aza-4⁵-phosphacyclohex-2-ene.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1657–1659, August, 2004.     

Synthesis and crystal structure of a cyanide-bridged one-dimensional nickel(II) complex with alternating [Ni(En)<Superscript>2</Superscript>]<Superscript>2+</Superscript> and [Ni(CN)<Subscript>4</Subscript>]<Superscript>2−</Superscript> ions

The complex [Ni(En)₂][Ni(CN)₄] · 3.5H₂O (I) (En = ethylenediamine) was synthesized by the reaction of [Ni(En)₂](ClO₄)₂ and K₂[Ni(CN)₄] in an H-shaped tube. The crystal structure of I has been determined by single-crystal X-ray analysis. The crystal of complex I is orthorhombic, space group Pnna with a = 28.151(3), b = 8.3946(8), c = 14.5441(13)Å, M =404.76, Z = 8, V = 3437.0(5)ų. The structure of complex I reveals infinite zigzag chains shaped structure are formed by cis-Ni(En)₂-μ-(NC)₂, cis-μ-(NC)₂Ni(CN)₂, and trans-μ-(CN)₂Ni(En)₂.     

Synthesis and crystal structure of bis(μ-periodato-<Emphasis Type="Italic">O,O′,O″</Emphasis>)bis(18-crown-6)dirubidium

A new binuclear complex, bis(μ-periodato-O,O′,O″)bis(18-crown-6)dirubidium [Rb₂(IO₄)₂(18-crown-6)₂] (I), is synthesized. Its crystal structure is studied by single-crystal X-ray diffraction analysis (space group P2₁/n, a = 11.942 Å, b = 8.394 Å, c = 19.664 Å, β = 101.08°, Z = 4, direct method, anisotropic full-matrix least-squares approximation, R = 0.030 for 2823 independent reflections, CAD-4 automated diffractometer, λMoK _α radiation). Complex I is binuclear and centrosymmetric, consisting of two cationic monomers [Rb(18-crown-6)]⁺ of the host-guest type linked through two tridentate IO ₄ ^? bridging ligands. The coordination polyhedron of the Rb⁺ cation (coordination number 9) can be described as a distorted hexagonal pyramid with a base of six O atoms of one 18-crown-6 ligand and one threefold vertex at three O atoms of the two IO ₄ ^? bridging ligands. The 18-crown-6 ligand has a usual crown conformation.     

Synthesis and structure of cobalt(III) α-dimethylglyoximates containing thiourea and [ZrF<Subscript>6</Subscript>]<Superscript>2−</Superscript> anion

Two novel coordination compounds of thiourea-containing trans-octahedral trans-dioximates of trivalent cobalt [Co(DH)₂(Tu)₂]₂[ZrF₆]·H₂O and [Co(NioxH)₂(Tu)₂]₂[ZrF₆]·3H²O, where DH^? is the monoanion of dimethylglyoxime, NioxH^? is the monoanion of 1,2-cyclohexanone dioxime, Tu is thiourea, are prepared and characterized by single crystal X-ray diffraction. The structures manifest pairwise an almost parallel and perpendicular arrangement of the Tu fragment in respect to the equatorial plane of the coordination core, accompanied by a development of non-bonding intramolecular π-π-and N-H...O-interactions affecting the structures of the compounds in question. The formation of the crystal structures is primarily governed by outer-sphere [ZrF₆]^2? anions and crystallization water molecules.     

Stabilization of [Sc(NCS)<Subscript>6</Subscript>]<Superscript>3−</Superscript> anion by [M(18C6)]<Superscript>+</Superscript> complexes in solvation systems

The [M(18C6)]₄[Sc(NCS)₆]Cl · nH₂O complexes were established to form in the solutions ScCl _x -Solv-MNCS-18C6, where Solv is ethanol, THF, acetonitrile, or isopropyl alcohol; M = Na, K; 18C6 is 1,4,7,10,13,16-hexaoxocyclooctadecane. X-ray diffraction analysis of [K(18K6)]₄[Sc(NCS)₆]Cl · 3.33H₂O showed that the thiocyanate ion was coordinated by Sc through the N atom. The structure consists of octahedral Sc(NCS) ₆ ^3? that are united via nonvalent K-S interaction with macrocyclic dimers [M(18C6)]₂ into chains. Each 18C6 molecule coordinates one K atom.     

Synthesis and crystal structure of [Et<Subscript>4</Subscript>N] [Cr(PzTp)Cl<Subscript>3</Subscript>] [PzTp<Superscript>−</Superscript> = Tetra(pyrazolyl) Borate]

Treatment of CrCl₃(THF)₃ with KPzTp in THF affords of the compound K[Cr(PzTp)Cl₃], and the K⁺ in this complex can be replaced by Et₄N⁺ in CH₂Cl₂. Well-defined green crystals of [Et₄N]r(PzTp)Cl₃] (I) suitable for X-ray diffraction are obtained at −₂0°C. In the anion the metal center shows a distorted octahedral geometry with the tetra(pyrazolyl) borate bonded as three N-donor tripod ligands and three chloride atoms completing the coordination sphere.     

Synthesis and structure of cobalt(III) dimethylglyoximate with [FeF<Subscript>5</Subscript>(H<Subscript>2</Subscript>O)]<Superscript>2−</Superscript> anion

A new complex [Co(DH)₂(Thio)₂]₂[FeF₅(H₂O)] · 2CH₃OH (where DH^? is dimethylglyoxime monoanion, Thio is thiourea molecule) was synthesized and its structure was determined. The coordination polyhedron of the Co(III) atoms in two centrosymmetric complex cations is an octahedron, formed by four N atoms of two dimethylglyoxime residues and two S atoms of coordinated Thio molecules. One of the Thio molecules is almost perpendicular to a metal cycle (the dihedral angle 87.8(1)°), which is responsible for realization of intermolecular hydrogen bond N-H···O (N···O 2.990(3) Å). The second Thio molecule is almost parallel to the equatorial CoN₄ fragment (the dihedral angle 159.4(1)°) to give rise to intramolecular π-π interaction between practically planar Thio molecule and one of the π-delocalized metal cycle. The Fe(III) coordination polyhedron is an octahedron, formed by five F atoms and by the O atom of coordinated water molecule. The key role in the crystal structure organization is played by intermolecular hydrogen bonds N-H···F, N-H···O, N-H···S, the intramolecular bonds O-H···O, formed by the donor NH₂ groups of a complex cation with the F atoms of the [FeF₅(H₂O)]^2? and the donor-acceptor groups of the Thio fragments.     

Relativistic coupled cluster calculations of the electronic structure of KrH<Superscript>+</Superscript>, XeH<Superscript>+</Superscript> and RnH<Superscript>+</Superscript>

Potential energy curves of NgH⁺ cations (Ng = Kr, Xe, Rn) were obtained by using four-component relativistic CCSD(T) coupled cluster calculations. Dissociation energies, equilibrium bond lengths, electronic properties, such as dipole moments and electric field gradients at the nuclei, and the related spectroscopic parameters of the electronic ground state have been determined. The results obtained for KrH⁺ and XeH⁺ are in good agreement with available experimental data, while those for RnH⁺ have been determined for the first time at this level of theory.     

Synthesis,structural and multinuclear natural abundance (<Superscript>13</Superscript>C, <Superscript>31</Superscript>P, <Superscript>195</Superscript>Pt) CP/MAS NMR studies of crystalline O,O′-dialkyldithiophosphate platinum(II) complexes

Platinum(II) O,O′-dicyclohexyl dithiophosphate [Pt{S₂P(O-cyclo-C₆H₁₁)₂}₂] (I) and platinum(II) O,O′-diisopropyl dithiophosphate [Pt{S₂P(O-iso-C₃H₇)₂}₂] (II) complexes were obtained and studied by solidstate ¹³C, ³¹P, and ¹⁹⁵Pt CP/MAS NMR spectroscopy. The dithiophosphate (Dtph) ligands in molecular structure I were found to be coordinated by platinum in S,S′-bidentate fashion to form the planar chromophore [PtS₄] (single-crystal X-ray diffraction data). For complex II, a new α-form (α-II) was obtained and identified by ³¹P MAS NMR spectroscopy. The ³¹P chemical shift anisotropy δ_aniso and the asymmetry parameter η of the ³¹P chemical shift tensor were calculated from the whole MAS spectra.     

Structure and stability of endohedral complexes <Superscript>4/2</Superscript>X@(HAlNH)<Subscript>2</Subscript> (X = N,P, As,C<Superscript>−</Superscript>, Si<Superscript>−</Superscript>)

The structures of a closo-hedral cluster (HAlNH)₁₂ and endohedral complexes ^4/2X@(HAlNH)₁₂ (X = N, P, As, C⁻, Si⁻) are studied by density functional theory (DFT) at the B3LYP/6-31G(d) level. The geometries, natural bond orbital (NBO), vibrational frequency (ν₁), energetic parameters, magnetic shielding constants (σ), and nucleus independent chemical shifts (NICSs) are discussed. It is found that all guest species are minima at the cage center. Inclusion energies (ΔE _inc) of all species are negative except those of ⁴N and ^4/2P. In all species, the endohedral quartet states (⁴X) are energetically less favorable than their doublet states (²X). The calculations predict that caged X states only donate <0.50 e to the cage and preserve their unencapsulated ground states.     

Synthesis and crystal structure of supramolecular compounds of cucurbituryl with the chalcocyanide cluster complex [Re<Subscript>4</Subscript>Te<Subscript>4</Subscript>(CN)<Subscript>12</Subscript>]<Superscript>4−</Superscript> and a manganese(II) aqua complex

Supramolecular compounds [Mn(H₂O)₄(C₃₆H₃₆N₂₄O₁₂)]₂[Re₄Te₄(CN)₁₂]·12.5H₂O (1), (H₃O)₂[{Mn(H₂O)₄ (C₃₆H₃₆N₂₄O₁₂)}{Mn(H₂O)₄} ₂{Re₄Te₄(CN)₁₂}₂]·3.5H₂O (2) and [{Mn(H₂O)₃Cl} ₂(C₃₆H₃₆N₂₄O₁₂)]Cl₂·6H₂O (3) were obtained by crystallization at room temperature from water solutions containing macrocyclic cavitand cucurbituryl (C₃₆H₃₆N₂₄O₁₂), aqua complex of manganese(II) (1–3) and chalcocyanide cluster complex [Re₄Te₄(CN)₁₂]^4? (1, 2). From XRD analysis, the cucurbituryl molecule is bound with one (1, 2) or two atoms of manganese (3) through oxygen atoms of carbonyl groups. Compound 2 has a chain structure where cluster complexes of rhenium are linked through bridge manganese atoms into a polymeric ribbon. Compounds 1 and 3 have the island-like type of structure.     

Thiophosphorylation of calix[4]resorcinarenes with 2,4-diaryl-1,3-dithia-2λ<Superscript>5</Superscript>,4λ<Superscript>5</Superscript>-diphosphetane 2,4-disulfides

Reactions of 2,4-diaryl-1,3-dithia-2λ⁵,4λ⁵-diphosphetane 2,4-disulfides with tetraheptylcalix[4]-resorcinarene and octa-O-(2-hydroxyethyl)tetraoctylcalix[4]resorcinarene gave the corresponding octakis(aryldithiophosphonic acids).     

Crystal and molecular structures of (<Emphasis Type="Italic">trans</Emphasis>-3,4-Diamino-2,2,6,6-tetramethylpiperidine-1-oxyl-N<Superscript>3</Superscript>,N<Superscript>4</Superscript>)(oxalato-O,O′)platinum(II)

The crystal and molecular structures of (trans-3,4-diamino-2,2,6,6-tetramethylpiperidine-1-oxyl-N³, N⁴)(oxalato-O,O)platinum(II) (C₁₁H₂₀N₃O₅Pt) are studied by X-ray diffraction analysis. The crystals are monoclinic: a=15.210 , b=7.222 , c=14.520 , =118.14°, Z=4, and space group P2₁/c. The structure is solved by the direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R=0.05 against 3227 independent reflections (CAD4 automated diffractometer, MoK ). A molecule of the complex is mononuclear with two different bidentate ligands. The coordination of the Pt²⁺ cation is a distorted square. The crystal contains intermolecular hydrogen bonds.Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 3, 2005, pp. 179–182.Original Russian Text Copyright © 2005 by Chekhlov.This revised version was published online in April 2005 with a corrected cover date.This revised version was published online in April 2005 with a corrected cover date.     

Mercury complex [(HOCH<Subscript>2</Subscript>)<Subscript>3</Subscript>CNH<Subscript>3</Subscript>]<Stack><Subscript>2</Subscript><Superscript>+</Superscript></Stack> [HgI<Subscript>4</Subscript>]<Superscript>2−</Superscript>: Synthesis and structure

The complex [(HOCH₂)₃CNH₃] ₂ ⁺ [HgI₄]^2? (I) was synthesized by reacting (trioxymethyl)methylammonium iodide with mercury dioide (2: 1 mol/mol) in acetone. X-ray crystallography shows that the complex consists of two types of crystallographically independent [(HOCH₂)₃CNH₃]⁺ cations and tetrahedral anions [HgI₄]^2? (IHgI, 106.49(2)°–113.99(4)°; Hg-I, 2.7849(8)-2.8105(8) Å. [(HOCH₂)₃CNH₃]⁺ cations are linked via hydrogen bonds O…H-N and O-H…N (O…N, 2.84–2.92 Å) to form polymer chains, which are cross-linked with one another via anions (I…H, 2.81, 2.82 Å).     

Synthesis and steric structure of 3,4-dimethyl-2-(3-methyl-1-phenylbuta-1,2-dienyl)-5-phenyl-1,3,2λ<Superscript>5</Superscript>-oxazaphospholane 2-oxide

Allenic 1,3,2-oxazaphospholanes on the basis of d-pseudoephedrine were synthesized. The steric structure of 3,4-dimethyl-2-(3-methyl-1-phenylbuta-1,2-dienyl)-5-phenyl-1,3,2λ⁵-oxazaphospholane 2-oxide was determined by X-ray diffraction.     

Stereo-dynamics study of O + HCl → OH + Cl reaction on the <Superscript>3</Superscript>A″, <Superscript>3</Superscript>A′, and <Superscript>1</Superscript>A′ states

Using three accurate potential energy surfaces of the ³A″, ³A′, and ¹A′ states constructed recently, we present a quasi-classical trajectory (QCT) calculation for O + HCl (v = 0, j = 0) → OH + Cl reaction at the collision energies (E _col) of 14.0–20.0 kcal/mol. The three angular distribution functions—P(q_r ) P(\theta_{r} ) , P(j_r ) P(\varphi_{r} ) , and P(q_r ,j_r ) P(\theta_{r} ,\varphi_{r} ) , together with the four commonly used polarization-dependent differential cross-sections, \frac2ps \fracds₀₀ dw_t , \frac2ps \fracds₂₀ dw_t , \frac2ps \fracds_{22 +} dw_t , \textand \frac2ps \fracds_{21 -} dw_t {\frac{2\pi }{\sigma }}\,{\frac{{d\sigma_{00} }}{{d\omega_{t} }}},\,{\frac{2\pi }{\sigma }}\,{\frac{{d\sigma_{20} }}{{d\omega_{t} }}},\,{\frac{2\pi }{\sigma }}\,{\frac{{d\sigma_{22 + } }}{{d\omega_{t} }}},\,{\text{and}}\,{\frac{2\pi }{\sigma }}\,{\frac{{d\sigma_{21 - } }}{{d\omega_{t} }}} are exhibited to get an insight into the alignment and the orientation of the product OH radical. There is a similar behavior of the tendency scattering direction for the two triplet electronic states (³A″ and ³A′)—backward scattering dominates, however, forward scattering prevails for the case of ¹A′ state. Also, obvious differences have been found in the stereo-dynamical information, which reveals the influences of the potential energy surface and the collision energy. The degrees of polarization and the influence of the collision energy on the stereo-dynamics characters of the title reaction are both demonstrated in the order of ³A′ > ³A″ > ¹A′.