Satoru Onaka

Substituent effects on aurophilicity and π–π interaction in crystals of arylphosphine–Au(I) derivatives. Synthesis and X-ray structural studies of compounds (CX3C6H4)3PAuX and {(CF3)2C6H3}3PAuX

Abstract Substituent effects on aurophilic interactions have been explored by single-crystal X-ray diffraction methods for a series of Au(I) complexes of monodentate phosphines, R′ 3 PAuX (X=Cl, Sph, and Spy). When a CF 3 substituent is introduced at a meta position of the phenyl ring in (C 6 H 5 ) 3 P, aurophilicity has been accrued in ClAuP( m -CF 3 C 6 H 4 ) 3 . However, aurophilicity has been weakened by introducing two CF 3 groups at both meta positions. When a CF 3 substituent is substituted for a H atom in the para position or when a CH 3 substituent is introduced in the meta and/or para positions, such an effect has not been observed for R′ 3 PAuCl and R′ 3 PAuSph. Most dimers constructed by aurophilicity appear to be reinforced by π–π interactions between the phenyl ring of the Sph ligand or the pyridine ring of the Spy ligand and one of the phenyl rings in the R′ 3 P ligand. A novel ladder-like supra molecular architecture is created in the crystal of {3,5-(F 3 C) 2 C 6 H 3 } 3 PAuSph, and a tetramer is formed in the crystal of (C 6 H 5 ) 3 PAuSpy by aurophilic and π–π interactions. Substituent effects on important bond lengths have been discussed.

Synthesis, X-ray molecular structure analysis, and study on ligand scrambling reactions of new thiolatogold(I) complexes with various phosphines

Abstract Treatment of Au(PPh3)Cl, (AuCl)2(trans-dpen) and (AuCl)2(dppfe) with Sn(SPh)(n-Bu)3 and/or PhSH/KOH affords Au(PPh3)(SPh) (1), (AuSPh)2(μ-trans-dpen) (2), (AuSPh)2(μ-dppfe) (3), (AuSPh)(μ-trans-dpen)(AuCl) (4), and (AuSPh)(μ-dppfe)(AuCl) (5) in good yields. All these thiophenolates are characterized by single crystal X-ray analysis, 1H and 31P NMR spectroscopy. 1 forms tetramer through Au⋯Au interaction and π–π interaction between the phenyl group in SPh and one of the phenyl groups in PPh3 in the solid state. An infinite chain structure is formed for 2 through intermolecular aurophilicity and these chains are connected by partial overlap (π–π interaction) of neighboring phenyl groups in SPh to give two-dimensional networks in the solid state. Similar infinite chains are formed through aurophilicity, but two-dimensional networks are not formed for 4 in the solid state. No multidimensional structure is formed for 3 and 5 in the solid state. 1H and 31P NMR spectroscopy of CDC13 solutions of 2, 3, 4, and 5 has revealed that rapid ligand scrambling takes place for 4 and 5.

Spectroscopic study of the interaction of tricyclopentadienides of lanthanoid elements with metal carbonyl derivatives. I

Abstract The interaction of samarium tricyclopentadienide, Cp 3 Sm, with a diverse series of metal carbonyl derivatives has been investigated by IR and 1 H NMR spectroscopy, and the variability of Lewis base sites in manganese carbonyl derivatives has been studied in terms of the charge on the manganese atom and the π-accepting ability of the ligands in these derivatives. In the series BrMn(CO) 5− x L x , the oxygen atom functioned as the Lewis base site, while the manganese atom was the site of the Lewis basicity in anions of the type [Mn(CO) 5- x L x ] − ( x = 0, 1, 2; L = P(OPh) 3 ). The reactivity of the carbonyl oxygen atom in the series Me 4- y Sn[Mn(CO) 5 ] y ( y = 1, 2, 3) was in the order: MeSn[Mn(CO) 5 ] 3 > Me 2 Sn[Mn(CO) 5 ] 2 > Me 3 SnMn(CO) 5 ; Cp 3 Sm induced an upfield shift of the methyl proton NMR signal in these SnMn compounds on adduct formation. Attempts to induce shifts of the terminal carbonyls to bridging positions in Mn 2 (CO) 10 [Mn(CO) 4 P(OPh) 3 ] 2 , and H 3 Mn 3 (CO) 12 led instead to complexation at terminal carbonyl ligands.

Construction of a Crystalline Tetramer and Infinite Network through the Dual Use of Au(I)···Au(I) and π-π Interactions

SC6H5 was substituted for Cl in AuCl(PPh3) and (AuCl)2(trans-Ph2PCH=CHPPh2) by reacting with Sn(SC6H5)(n-Bu)3 in refluxing THF. Both products exhibit new three-dimensional motifs which are created by Au···Au interaction and π-π interaction between phenyl rings in crystals.

Crystal structural properties of a pinwheel compound: [36](1,2,3,4,5,6)cyclophane

In the crystal structures of [3 6 ](1,2,3,4,5,6)cyclophane 1 and the 1 :TCNQ (1:1) complex, the cyclophane moiety is observed as the D 6 h structure because of the disorder of the molecules with C 6 h symmetry. In contrast, the C 6 h structure is observed in the crystals of the 1 :TCNQ-F 4 (1:1) complex, and the complex shows an alternating donor–acceptor stacking with partial donor–acceptor overlap.

Rational synthesis and X-ray structural study of manganese–pyridine–alcohol derivatives

Systematic syntheses of manganese derivatives with 2-pyridineethanol, 2-pyridinemethanol and 2,6-pyridinedimethanol as chelating ligands have been undertaken to produce [trans-Mn(C5H4N-2-CH2CH2OH)2Cl2] (1), [cis-Mn2(μ-Cl)2(Cl)2(C5H4N-2-CH2CH2OH)2(OH2)2] (2), [cis-Mn2(μ-Cl)2(C5H4N-2-CH2OH)4]Cl2 (3) and [MnCl{η3-C5H3N-2,6-(CH2OH)2}{η2-(C5H3N-2,6-(CH2OH)2)}]Cl (4). The complexes were characterized by single-crystal X-ray diffraction. The oxidation state of the manganese ions in these complexes is 2+. Magnetic data are measured down to 2 K; in dimer complexes (2 and 3) a significant antiferromagnetic interaction is observed between two manganese ions.

REACTION AND X-RAY MOLECULAR STRUCTURAL STUDY OF SOME MANGANESE SULFUR CLUSTERS

Abstract [Mn(CO)3]2(μ-SPh)2(μ-dppfe) (1) has been synthesized by treatment of Mn4(SPh)4(CO)12 (2) with Me3NO followed by reaction with dppfe (dppfe = 1,1′-bis(diphenylphosphino)ferrocene). 1 is also synthesized from Mn2(SPh)2(CO)8 (3) by the same procedure as above in an improved yield. The molecular structures of these three manganese-sulfur derivatives have been determined by single crystal X-ray diffraction techniques. The geometry around the manganese atoms in 1 is severely distorted from octahedral, while the distortions from octahedral arrangement are lessened in 2 and 3. The Mn … Mn separation (3.675(5) A) in 1 is close to those of 2 and 3.

The infrared intensities of the carbonyl stretching modes of a series of compounds, X3M—Mn(Co)5 (X = Cl, Br and I; M = Si, Ge and Sn)

The i.r. intensities of the carbonyl stretching vibrations of a series of compounds, X3M—Mn(CO)5(X = Cl, Br and I; M = Si, Ge and Sn) with C4ν, local symmetry around the manganese atom have been measured. The intensities of the A1 mode of the four planar carbonyl groups increase as the halogen atom changes from Cl to I and/or the IVb metal atom changes from Si to Sn, and these increases correlate with the decrease of the metal-metal stretching force constants. This relationship between the i.r. intensities and the metal-metal stretching force constants can be interpreted in terms of the interaction of the IVb metal-manganese σ-orbitals with the π∗ (radial) orbitals of the four planar carbonyl groups.

Nuclear quadrupole resonance of halogens in trihalotin manganese pentacarbonyls, X3SnMn(CO)5

Abstract The nuclear quadrupole resonance of halogens in X3SnMn(CO)5, where X stands for chlorine, bromine, and iodine, was observed between liquid nitrogen and room temperatures. Trichlorotin and tribromotin manganese pentacarbonyls gave rise to a sextet and a quintet of resonance lines, respectively, at liquid nitrogen temperature. The intensity of the central line of the quintet was twice as strong as the other lines. The resonance patterns of these compounds bear a strong resemblance to each other indicating the formation of crystals of a similar structure. Triiodotin manganese pentacarbonyl showed six v1, frequencies in the temperature range studied indicating the presence of six nonequivalent iodine atoms in crystals. The temperature dependence of chlorine resonance frequencies suggests the possibility of internal reorientation of SnCl3 groups in crystals. The ionic character of tin-halogen bonds was evaluated by use of the Townes-Dailey procedure.

Synthesis and X-ray Molecular Structure Analysis of Some Au-Co, Au-Mn, and Hg-Co Bonded Compounds

The reaction of NaCo(CO)4-x (PR3) x (x = 0, 1) with Au(PR3)Cl was examined in THF. The products were characterized by single crystal X-ray analysis and/or XPS spectroscopy. When the THF solution of NaCo(CO)4-x (PR3) x which was in situ prepared by the reduction of the corresponding cobalt carbonyl dimer with Na amalgam was filtered, the main product was (R3P)Au-Co(CO)4 and (R3P)Au-Co(CO)4-x (PR3) x (x = 1,2); phosphine migration from the Au to the Co site was observed for bulky phosphines during the recrystallization process. When the THF solution of NaCo(CO)4-x (PR3) x was not filtered, the main product had the composition of M[Co(CO)3(PR3)]2. The element M was clearly determined to be Hg by XPS spectroscopy. The reaction of NaMn(CO)5 with Au(PR3)Cl, however, afforded R3PAu-Mn(CO)5. The bonding parameters such as Au-M and Hg-Co bond-lengths were interpreted in terms of the electronic nature of the R group of the monodentate PR3 ligand.