Volume 57, Issue 3

[Cu 2 (L)(O 2 CMe)· 1 / 2 H 2 O (L = 1,3-bis (2-hydroxy-5-chlorosalicylideneamino)propan-2-ol) was synthesized and its crystal structure determined. (C 19 H 16 N 2 O 5 Cl 2 Cu 2 )· 1 / 2 H 2 O, monoclinic, space group P 2 1 /c, a = 20.660(10), b = 9.618(2), c = 21.810(10) Å 3 , β = 109.3(8)­­°, V = 4090(2) Å 3 , Z = 8. The crystal contains two independent dicopper(II) complexes and an uncoordinated molecule of water in the asymmetric unit. In both molecules of the asymmetric unit, the two copper(II) ions are bridged by the alkoxo group of the ligand and by an acetato group. Magnetic susceptibilities of the complex in the solid state were measured over the temperature range 4.6 - 308 K. The title compound shows weak antiferromagnetic coupling with a best fit J value of -89.6 cm -1 , which is interpreted in terms of a compensation effects of the different bridging ligands which participate in the super-exchange interactions. Ab initio restricted Hartree-Fock calculations have shown that the acetato bridge and the alkoxide bridge contribute to the magnetic interaction countercomplementarily to reduce antiferromagnetic interaction.

Cationic ruthenium sulfine complexes [CpRu(PR´ 3 ) 2 (O=S=CHR)]PF 6 have been obtained by a variety of methods. Oxidation of the thioaldehyde complexes [CpRu(PR´ 3 ) 2 (S=CHR)]PF 6 with either 2-tosyl-3-phenyl-oxaziridine (PR´ 3 = PMe 3 ) or magnesium-monoperoxyphthalate (PR´ 3 = 1/2 dppm) gave complexes of arylsulfines (R = Ph, 3-C 6 H 4 F, 4-C 6 H 4 Cl, 4- C 6 H 4 OMe) selectively in their thermodynamically less stable E form. Siloxane elimination from the sulfinato complexes [CpRu(PMe 3 ) 2 (SO 2 CHRSiMe 3 )] yielded complexes of aliphatic sulfines, [CpRu(PMe 3 ) 2 (O=S=CHR)]PF 6 (R =H,Me). Treatment of [CpRu(dppm)(SO 2 CH 2 R)] with acetyl chloride led to an oxygen redistribution giving complexes of thioaldehydes [CpRu(dppm)(η 2 -S=CH 2 )]PF 6 and [CpRu(dppm)(η 1 -S=CHR)]PF 6 (R = Ph, 4-C 6 H 4 Cl). The structure of the latter was determined by X-ray crystallography. The loss of oxygen can be suppressed by performing the acylation-elimination sequence in the presence of poly-(4-vinylpyridine). This provided a selective access to complexes of Z-sulfines, [CpRu(PMe 3 ) 2 (O=S=CHR)]PF 6 (R = Ph, 4-C 6 H 4 Cl) and [CpRu(dppm)(O=S=CHR)]PF 6 (R = Ph, 4-C 6 H 4 Cl, COOEt, Cl). Complexes of the parent sulfine O=S=CH 2 were also obtained by SO transfer to the methylene complex [CpRu(PMe 3 ) 2 (CH 2 )]PF 6 and methylene transfer to the sulfur monoxide complex [Cp*Ru(PMe 3 ) 2 (SO)]PF 6 . Most of the new sulfine complexes exhibit dynamic behaviour in solution, i. e. ligand rotation, ligand inversion, and η 2 /η 1 hapticity change. O-Alkylation provided the dicationic complex [CpRu(PMe 3 ) 2 (EtO-S=CHMe)](PF 6 ) 2 , and S-oxidation gave the sulfene complexes [(C 5 R 5 )Ru(PMe 3 ) 2 (O 2 S=CH 2 )]PF 6 (R = H, Me).

Ternary intermetallic compoundsREPdCd (RE=La, Ce, Pr, Nd, Sm, Eu, Tb)were synthesized by reaction of the elements in sealed tantalum tubes in a high-frequency furnace. All compounds were investigated by X-ray diffraction on powders. Those with RE = La, Ce, Pr, Nd, Sm, and Tb contain trivalent rare earth metals and they crystallize with the hexagonal ZrNiAl type structure. NdPdCd [a = 764.8(3), c = 401.3(2) pm] and TbPdCd [a = 756.5(2), c = 389.0(1) pm] are reported here for the first time as well as EuPdCd. The compounds with La, Ce, Pr, and Sm [J. Alloys Compd. 182, 87 (1992)] are confirmed. The crystal structure of EuPdCd was refined from X-ray single crystal diffractometer data: TiNiSi type, Pnma, a = 745.9(3), b = 439.8(2), c = 863.7(3) pm, wR2 = 0.0405, 683 F 2 values, and 20 variable parameters. The three-dimensional [PdCd] substructure consists of strongly puckered, orthorhombically distorted Pd 3 Cd 3 hexagons with Pd-Cd distances ranging from 283 to 285 pm. The europium atoms fill the cavities within the [PdCd] network. Chemical bonding in the series REPdCd and REPdIn is compared.

Reactions of the palladium(II) complexes trans-Cl 2 Pd(L-NH 2 CHRCO 2 Me) 2 with AgBF 4 in dichloromethane give the cationic chelate complexes [Pd(L-NH 2 CHRCO 2 Me) 2 ] 2+ (BF 4 -) 2 (R =CHMe 2 , CMe 3 , CH 2 CHMe 2 , CH 2 Ph, CH 2 CO 2 Me) inwhich the α-amino acid methylesters function as bidendate ligands. The complexes 1 - 5 are highly sensitive towards water.

A series of fifteen new N-substituted derivatives of 2,3-dihydro-2,2-dimethyl-7-benzofuranol have been prepared and studied by IR and 1 H NMR spectroscopy. In addition the crystal structures of 7-[3-[4-(4-fluorophenyl)-1-piperazinyl]propoxy]-2,3-dihydro-2,2-dimethylbenzofuran (16), 7-[3-(4-phenyl-1-piperazinyl)propoxy]-2,3-dihydro-2,2-dimethylbenzofuran (18) and 7-[3-(4-benzyl-1-piperazinyl)propoxy]-2,3-dihydro-2,2-dimethylbenzofuran (20) have been solved by X-ray structure analysis of single crystals. The crystals of two of them (16 and 18) are isostructural and there are only small differences between their molecular geometries. Greater differences are observed in the crystal structure of the compound 20 due to the presence of a benzyl fragment instead of a phenyl one. The compound 10 (7-(3-t-butylamino-2-hydroxypropoxy)- 2,3-dihydro-2,2-dimethylbenzofuran hydrochloride), screened for basic parameters of rats circulatory system, displayed an effect of decreasing of arterial blood pressure and heart rate

Hydroboration of propyne and 1-butyne with HBCl 2 obtained from BCl 3 and Me 3 SiH in equimolar amounts leads to 1,1-bis(dichloroboryl)alkanes 1. When BCl 3 is used in excess, no 1,1-bis(dichloroboryl)alkanes 1 but E-1-dichloroborylalkene 2 besides E-1-dichloroboryl-2- chloro-alk-1-ene 3 are formed. Other by-products are tris(2-chloro-alk-1-ene-1-yl)borane 4 and bis(2-chloro-alk-1-ene-1-yl)chloroborane 5. The reaction of 3 with catechol and the formation of pyridine adducts of 4 and 5 lead to crystalline products. The composition of the products was determined by NMR spectroscopy, MS spectrometry and X-ray structure analyses of 6a, 6b, 7a and 8b.

The electronic spectra and the photochemistry of the uranyl complexes UO2 (salophen) and UO 2 (oxinate) 2 with H 2 salophen = N,N´-bis(salicylidene)-o-phenylenediamine and oxine = 8- hydroxyquinoline were studied. The excited state behavior of both complexes is determined by a low-energy salophen 2- / oxinate - to U(VI) ligand-to-metal charge transfer (LMCT) state which is not luminescent but can be reactive. In the case of UO 2 (oxinate) 2 the photolysis leads to the formation of free oxine with ϕ = 3.6 x 10 -3 at λ irr = 366 nm in CHCl 3 . It is suggested that various redox processes with the participation of the solvent are involved in product formation. UO 2 (salophen) is not light sensitive since the primary electron transfer is followed by recombination which is facilitated by the rigid UO 2 (salophen) structure.

57 Fe NMR spectra (11.66 MHz) of the 1,1-diorganosila-[1]ferrocenophanes, [Fe(C 5 H 4 ) 2 ] - SiR 1 R 2 (1) (R 1 = R 2 = Me) and (2) (R 1 = Me, R 2 = Ph), the 1-chloro-1-organosila-[1]ferrocenophanes [Fe(C 5 H 4 ) 2 ]Si(Cl)R 1 3 (R 1 =Me) and 4 (R 1 = Ph), and of 1,1-dichlorosila-[1]ferrocenophane, [Fe(C 5 H 4 ) 2 ]SiCl 2 5, were measured. All 57 Fe resonance signals are shifted to lower frequencies with respect to ferrocene, the largest shift being observed for 5 (-147.7 ppm). The influence of chloro substituents at silicon in comparison to organo groups is much more pronounced in the ferrocenophanes than in non-cyclic 1-silyl- or 1,1-di(silyl)-ferrocene derivatives. In the case of -2,2,6,6-tetramethylpiperidin-1-yl-phospha-[1]ferrocenophane, [Fe(C 5 H 4 ) 2 ]P(tmp) 6, the 57 Fe nucleus is deshielded (129.8 ppm) with respect to ferrocene, and the coupling constant 2 J( 57 Fe, 31 P) = 3.4 Hz was measured for the first time.

In a 4-isopropyl-1-oxa-3-oxonia-2-borata-naphthalene the isopropyl group exhibits the same conformational phenomena as the Me 2 N group in 8-dimethylamino-naphth-1-yl-silanes and related phosphorus compounds. Since the details can be fully rationalized on the basis of the steric situation and electronic factors are excluded, the common features cannot serve to infer dative interaction from nitrogen to silicon / phosphorus resulting in hypercoordination of the third period element atoms in the reference compounds.

A new polymorph of the copper(II) thiocyanate complex with 2-dimethylaminoethanol, [Cu 2 (Me 2 Ea) 2 (NCS) 2 ] ∞ (HMe 2 Ea = 2-dimethylaminoethanol, HL) 1, was isolated in the attempted synthesis of a mixed-metal complex from zerovalent copper, cadmium oxide and ammonium thiocyanate in CH 3 CN solution of HL in air. [Cu 2 (Me 2 Ea) 2 (NCS) 2 (DMSO) 2 ] 2 is a product of recrystallization of 1 from DMSO. X-ray analysis carried out on single crystals for both compounds revealed that 1 is a rare example of a 1D coordination polymer consisting of two chains in which the metallic centres are connected through single end-to-end NCS groups. The chains are inter-linked through alkoxo-bridges of L groups between the neighboring copper atoms. Complex 2 is a centrosymmetric dimer composed of two CuL(NCS)DMSO units linked by alkoxo-bridges of L groups.

Two new natural xanthones, 1,3,5-trihydroxy-8-methoxyxanthone (1) and 3,5-dihydroxy-8- methoxy-1-O-β-D-glucopyranosyl xanthone (2) were isolated along with two known xanthones from Gentiana azurium Bunge (Fam. Gentianaceae). Their structures were determined on the basis of their spectral data.

From a terrestrial Streptomycete, GW 10/2517, the new 5-(2-methylphenyl)-4-pentenoic acid (1a) was isolated. The structure of 1a was proven by a detailed spectroscopic analysis and by synthesis.

Starting from (1R)-(+)-camphor, the reaction with cyclopentadienylmagnesium chloride gave the corresponding tertiary alcohol 1, which was transformed into the optically active pentafulvene 5-(1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)cyclopentadiene (2) by acidcatalyzed water elimination. Deprotonation with tert-butyllithium yielded the corresponding lithium 5-{(1R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-en-2-yl}cyclopentadienide (3), which was converted into the non-racemic 1,1β-bis{(1R)-1,7,7-trimethylbicyclo[2.2.1]hept-2-en-2- yl}ferrocene (4). 4 forms orthorhombic crystals of the space group P2 1 2 1 2 1 with a = 7.7163(4), b = 10.7381(6), and c = 28.804(2) A˚ , which have been subjected to X-ray diffraction.

Two amide libraries, Fmoc-[Lys(ac i )] 4 -Gly-resin (1) (ac i = 2-naphthylcarbonyl, 1-adamantylcarbonyl and benzyloxycarbonyl) and Fmoc-[δ-Glu(α-amide i )] 4 -Gly-resin (2) (amide i = morpholineamide, piperidineamide, (N´-phenyl)-piperazineamide), have been synthesized from the corresponding Fmoc-protected amino acid derivatives. Beads of the libraries complex organic dyes (crystal violet and Sudan black) differently according to the sequence of residues in 1 or 2. The results are considered a step towards artificial receptors for small organic molecules build from linear oligoamides.

1,3-Bis(arylsulfonyl)-benzimidazolones 1a-d were synthesized by reacting benzimidazolones with arenesulfonyl chlorides in the presence of NaOH. Mono(arylsulfonyl)-benzimidazolone derivatives 5a-c were prepared from benzimidazolone by protecting one of the Natoms with a tert-butoxycarbonyl group followed by arylsulfonylation and deprotection in acidic medium. The antidiabetic activity of three compounds 1a, 1c and 5a has been determined.

A 2-aminomethyl-15-crown-5 (AM15C5) bonded Merrifield peptide resin was synthesized. The capacity of this crown ion exchanger was 2.25 meq/g of dry resin. The heavier isotopes of magnesium were enriched in the solution phase, while the lighter isotopes were enriched in the resin phase. The hydration and isotope mass effects dominated over those of the complexation and properties of the exchanger. The separation factors of 24 Mg 2+ / 25 Mg 2+ , 24 Mg 2+ / 26 Mg 2+ , and 25 Mg 2+ / 26 Mg 2+ isotope pair fractionations were 1.0012, 1.0023, and 1.0011, respectively.

The first labortory synthesis and characterization of the mineral Nadorite, PbSbO 2 Cl, is reported. The material was synthesized by combining PbCl 2 , PbO and Sb 2 O 3 . Powder X-ray diffraction data on the polycrystalline product is consistent with the previously reported crystal structure on the mineral. Infrared and thermogravimetric data are also present.