Metal-phenoxyalkanoic acid interactions. Part 20. The crystal structures of diaquabis(2-carbamoylphenoxyacetato)-copper(II) and tetraaquabis(2-carbamoylphenoxyacetato)nickel(II)

The crystal structures of two metal(II) complexes of 2-carbamoylphenoxyacetic acid (salicylamide-O- acetic acid, (SAH)) have been determined by X-ray methods. The first, diaquabis(2-carbamoylphenoxyacetato)copper(II) (1), forms triclinic crystals, space group P1 with 1 molecule in a unit cell of dimensions a = 4.0796(4), b = 9.936(1), c = 13.020(2) Å, α = 103.88(1), β = 107.00(1), γ = 97.61(1)°. The complex units are centrosymmetric monomers involving unidentate, trans-related acid ligands bonded through the phenoxy carboxylate oxygen [CuO, 1.933(2)] with two water ligands [CuOw, 1.961(3) Å] completing a square planar coordination about the central Cu(II) atom. Tetraaquabis(2-carbamoylphenoxyacetato)nickel(II) (2), is monoclinic, space group P2/c with 2 molecules in a unit cell of dimensions a = 10.957(2), b = 4.996(1), c = 20.042(4) Å, β = 105.51(2)°. These complex units are discrete centrosymmetric monomers involving unidentate, trans- related acid ligands bonded through the phenoxy carboxylate oxygen [NiO, 2.072(2) Å] with four water ligands [NiOw (mean), 2.069(2) Å] completing an almost regular octahedral coordination around the central Ni(II) atom. In both complexes, inter and intramolecular hydrogen bonding aids complex and crystal lattice stability

Metal-(phenylthio)acetic acid interactions-IV. The crystal structure of tetra-μ-[(2,4-dichloro-5-methylphenylthio)acetato-O,O′]-bis[acetonecopper(II)], a dimeric complex having coordinated acetone molecules

The crystal structure of the acetone adduct of copper(II) (2,4-dichloro-5-methylphenylthio)acetate has been determined by single crystal X-ray diffraction and refined by least squares to 0.051 for 3701 "observed" reflections. Crystals of the compound are triclinic, space group P1 with one dimer in a cell with a = 8.357(1), b = 12.502(2), c = 13.721(2) Å, α = 107.20(1), β = 96.09(1), γ = 104.94(1)°. The complex is a tetracarboxylate bridged dimer of the copper acetate hydrate type, with a CuCu separation of 2.646(1) Å and a mean CuO (equatorial) distance of 1.961(4) Å, while the axial positions of the dimer are occupied by coordinated acetone molecules [CuO, 2.206(3) Å]. X-ray crystal data and the results of chemical analyses are also presented, indicating that a second chemical polymorph has both acetone and water molecules, with a similar dimeric structure but having solvated acetone

Metal-(phenylthio)acetic acid interactions. Part 1. The crystal structures of (phenylthio)acetic acid, diaqubis[(phenylthio)acetato]zinc(II), and catena{aquabis[(phenylthio)acetato]cadmium(II)}

Crystal structures of (phenykthio)acetic acid (PTAH) (1), and the zinc(II) and cadmium(II) complexes of the PTAH have been determined by X-ray diffraction. The acid, PTAH, is monoclinic, space group P2/n, with Z = 4 in a cell of dimension a = 7.666(1), b = 5.638(1), c = 18.939(2) Å, β = 99.33(1)°. The molecules are planar and exist as centrosymmetric hydrogen bonded cyclic dimers. The thioacetic sode chain has synplanar-synplanar conformation. The Zn(II) complex, [Zn(PTA)(HO)], (2), is monoclinic, space group C2/c, with Z = 4, in a cell of dimensions, a = 32.048(11), b = 5.314(2), c = 10.725(3) Å, β = 101.20(2)°. (2) is monomeric with a distorted octahedral MO coordination involving four oxygens from two symmetrical bidentate PTA carboxyl groups [ZnO, 2.176(4), 2.204(3) Å] and two form cis-related waters [ZnO, 2.002(4)]. [Cd(PTA)(HO)] (3) is orthohombric, space group Pca2, Z = 4, with a = 33.826(8), b = 5.119(1), c = 9.872(3) Å, having an octahedral MOS coordination sphere consisting of one water [CdO, 2.294(10) Å], an oxygen and a sulphur from one PTA ligand [Cd), 2.335(10) Å, CdS, 2.738(5) Å] and an oxygen from the second PTA ligand [CdO, 2.276(10) Å]. The second carboxyl oxygen from each PTA ligand complexes the fifth and sixth coordination sites [Cd), 2.263(12), 2.254(10) Å] and bridges adjacent complex centres giving a polymeric structure

Metal-(phenylthio)acetic acid interactions. Part 3. The crystal structures of anhydrous barium (phenylthio)acetate and the potassium (phenylthio)acetate-(phenylthio)acetic acid adduct

The crystal structures of barium and potassium complexes of (phenylthio)acetic acid (PTAH) have been determined using X-ray diffraction. The barium analogue, [Ba(PTA)](1) is monoclinic, space group C2 with Z = 2, a = 7.219(4), b = 5.894(2), c = 19.272(2) Å, β = 91.57(4)°. [K(PTA)(PTAH)](2) is triclinic, space group P1 with Z = 2, a = 6.272(1), b = 7.222(1), c = 18.459(3) Å, α = 97.23(1), β = 93.64(1), γ = 97.31(1)°. The structures of (1) and (2) were refined to residuals of 0.047 and 0.053 for 844 and 2628 'observed' reflections respectively. The MO coordination about Ba in (1) is distorted 'cubic' with four oxygens from two bidentate carboxylate groups [BaO, 2.86, 2.97(3) Å] and four oxygens from adjacent carboxylates [BaO, 2.68, 2.69(2) Å] forming an infinite 2-dimensional polymer structure. (2) is polymeric and has bonded PTA as well as adducted PTAH species. There are seven KO contacts ranging from 2.729-3.034(3) Å from both PTA and PTAH species in an irregular coordination

Metal phenoxyalkanoic acid interactions-36. The preparation and crystal structures of tetraaquabis(2-phenoxybenzoato)nickel(ii) dihydrate, diaquabis(4-fluorophenoxyacetato)zinc(ii), catena-diaquabis(phenoxyacetato)cobalt(ii) and tetrakis-μ-[(pentafluorophenoxy)acetato(o,o′)] bis[aquacopper(ii)]

The structures of four complexes involving divalent first-row transition metals and phenoxy substituted carboxylic acids have been determined by X-ray diffraction. These are tetraaquabis(2-phenoxybenzoato)nickel(II) dihydrate (1), diaquabis(4-fluorophenoxyacetato)zinc(II) (2), diaquabis(phenoxyacetato)cobalt(II) (3) and tetrakis-μ-(pentafluorophenoxyacetato)bis[aquacopper(II)] (4). Complex 1 is regular octahedral with trans-related unidentate carboxylate [Ni-O (carboxylate) 2.031(1) Å] and four waters [Ni-O 2.049, 2.104(2) Å]. Complex 2 has a skew trapezoidal bipyramidal stereochemistry, involving four oxygens from two asymmetric bidentate carboxylates [Zn-O 2.107, 2.332(3) Å] and two waters [Zn-O 1.989(4) Å]. The polymeric complex 3 is isomorphous and isostructural with the manganese(II) analogue, with centrosymmetric octahedral CoO stereochemistry comprising four bonds to carboxylate oxygens (both bridging) [Co-O 2.076, 2.087(3) Å] and two to waters [Co-O 2.134(3) Å]. Complex 4 is a pseudo-centrosymmetric tetracarboxylate bridged dimer of the copper(II) acetate hydrate type with a Cu-Cu separation of 2.644(4) Å. Bond distances to copper are 1.96(1) (average, equatorial) and 2.15(1) Å (average, axial, to water)

Surgical Outcome of Medial Rectus Resection in Recurrent Exotropia: A Novel Surgical Formula

Purpose. To evaluate the surgical outcomes of unilateral or bilateral medial rectus (MR) muscle resection for recurrent exotropia after bilateral lateral rectus (BLR) muscle recession based on a novel surgical formula. Methods. Forty-one consecutive patients with unilateral or bilateral MR muscle resection for recurrent exotropia after BLR muscle recession were included in this retrospective study. All surgeries were performed according to the formula: 1.0 mm MR muscle resection for every 5 prism dioptres (PD) of exotropia, with an addition of 0.5 mm to each MR muscle operated on. Results. The mean recurrent exotropia distant deviation was 28 PD ± 11.2 (range 14 to 55 PD). Overall at postoperative 1 month, 36 (88%) achieved successful outcomes, 4 (10%) had undercorrection, and 1 (2%) had overcorrection. At postoperative 6 months, 29 (71%) achieved successful outcomes, 12 (29%) had undercorrection, and none had overcorrection. Subgroup analysis showed no statistically significant difference in success rates between unilateral and bilateral MR groups. Conclusion. Unilateral or bilateral MR muscle resection using our surgical formula is a safe and effective method for calculating the amount of MR resection in moderate to large angle recurrent exotropia, with a low overcorrection rate

Clinical Study Surgical Outcome of Medial Rectus Resection in Recurrent Exotropia: A Novel Surgical Formula

properly cited. Purpose. To evaluate the surgical outcomes of unilateral or bilateral medial rectus (MR) muscle resection for recurrent exotropia after bilateral lateral rectus (BLR) muscle recession based on a novel surgical formula. Methods. Forty-one consecutive patients with unilateral or bilateral MR muscle resection for recurrent exotropia after BLR muscle recession were included in this retrospective study. All surgeries were performed according to the formula: 1.0 mm MR muscle resection for every 5 prism dioptres (PD) of exotropia, with an addition of 0.5 mm to each MR muscle operated on. Results. The mean recurrent exotropia distant deviation was 28 PD ± 11.2 (range 14 to 55 PD). Overall at postoperative 1 month, 36 (88%) achieved successful outcomes, 4 (10%) had undercorrection, and 1 (2%) had overcorrection. At postoperative 6 months, 29 (71%) achieved successful outcomes, 12 (29%) had undercorrection, and none had overcorrection. Subgroup analysis showed no statistically significant difference in success rates between unilateral and bilateral MR groups. Conclusion. Unilateral or bilateral MR muscle resection using our surgical formula is a safe and effective method for calculating the amount of MR resection in moderate to large angle recurrent exotropia, with a low overcorrection rate

Metal-(phenylthio)alkanoic acid interactions-X. The crystal structures of thallium(I) (phenylthio)acetate(phenylthio)acetic acid adduct, caesium (2,4-dichloro-5-methylphenylthio)acetate(2,4-dichloro-5-methylphenylthio)acetic acid adduct, caesium (phenylthio)acetate(phenylthio)acetic acid adduct and caesium 2-(phenylthio)propionate monohydrate

Crystal structures of four univalent metal complexes with (phenylthio)acetic acid (PTAH), (2,4-dichloro-5-methylphenylthio)acetic acid (DCMPTAH), and 2-(phenylthio) propionic acid (PTPAH) have been determined using X-ray diffraction. The thallium complex, [Tl(PTA)(PTAH)], (1) is orthorhombic, space group Pccn, Z = 4, a = 10.466(6), b = 26.75(1), c = 6.013(2) Å. [Cs(DCMPTA)(DCMPTAH)], (2) is triclinic, space group Pl, Z = 1, a = 5.159(3), b = 6.898(3), c = 16.500(8) Å, a = 90.04(4), β = 94.22(4) and γ = 103.27(4)°. PTAH forms an adduct [Cs(PTA)(PTAH)], (3) which is monoclinic, space group Cc with Z = 4, a = 35.88(1), b = 7.201(2), c = 6.907(1) Å, β = 91.19(2)°. PTPAH forms a conventional hydrated complex, [Cs(PTPA)(HO)], (4), which is orthorhombic, Pbca, with Z = 8, a = 8.849(4), b = 9.500(3), c = 29.78(1) Å. The structures (1-4) were refined to residuals of 0.078, 0.087, 0.030 and 0.036 for 1353, 1571, 2225, 1807 "observed" reflections, respectively. Both 1 and 2 are examples of acid salts of the type, MHX, where X and HX are crystallographically equivalent. The molecules are polymeric and have bonded ligands as well as adducted acid species. 3 is an example of a type B (MX·HX) salt with X and HX crystallographically different. 4 is an example of a normal Cs salt. The Tl compound (1 is disordered with only half the general position sites occupied by the metal atom. Each site is at the centre of a distorted MOS octahedron with very short bonds to both asymmetric bidentate and bridging carboxylate groups [TlO, 2.22, 2.44(1) Å] and to the thioether S [TlS,2.517(4)Å]. In 2, the Cs atom is at the centre of symmetry of a distorted MO octahedron. It has a polymer structure with acetate bridges linking consecutive Cs atoms and carboxylate oxygen also bifurcated between two Cs atoms. The CsO distances are 3.123(10), 3.152(8) and 3.237(8)Å. Complex 3 has an irregular MO polyhedron about Cs with bonds from both PTA and PTAH ligands [CsO range, 3.03-3.45(1) Å; mean, 3.23(1) Å], and extends into a 2-D polymer structure. Compound 4 is also polymeric but with distorted octahedral MO coordination, bridging through both carboxylate and water oxygens [CsO range, 3.02-3.33(1) Å; mean, 3.20(1) Å]

Acetylcysteine for prevention of acute deterioration of renal function following elective coronary angiography and intervention

Context The antioxidant acetylcysteine prevents acute contrast nephrotoxicity in patients with impaired renal function who undergo computed tomography scanning. However, its role in coronary angiography is unclear.Objective To determine whether oral acetylcysteine prevents acute deterioration in renal function in patients with moderate renal insufficiency who undergo elective coronary angiography.Design and Setting Prospective, randomized, double-blind, placebo-controlled trial conducted from May 2000 to December 2001 at the Grantham Hospital at the University of Hong Kong.Participants Two hundred Chinese patients aged mean (SD) 68 (6.5) years with stable moderate renal insufficiency (creatinine clearance &lt;60 mL/min [1.00 mL/s]) who were undergoing elective coronary angiography with or without intervention.Intervention Participants were randomly assigned to receive oral acetylcysteine(600 mg twice per day; n = 102) or matching placebo tablets (n = 98) on the day before and the day of angiography. All patients received low-osmolality contrast agent.Main Outcome Measures Occurrence of more than a 25% increase in serum creatinine level within 48 hours after contrast administration; change in creatinine clearance and serum creatinine level.Results Twelve control patients (12%) and 4 acetylcysteine patients (4%) developed a more than 25% increase in serum creatinine level within 48 hours after contrast administration (relative risk, 0.32; 95% confidence interval [CI], 0.10-0.96; P = .03). Serum creatinine was lower in the acetylcysteine group (1.22 mg/dL [107.8 &micro;mol/L]; 95% CI, 1.11-1.33 mg/dL vs 1.38 mg/dL [122.9 &micro;mol/L]; 95% CI, 1.27-1.49 mg/dL; P = .006) during the first 48 hours after angiography. Acetylcysteine treatment significantly increased creatinine clearance from 44.8 mL/min (0.75 mL/s) (95% CI, 42.7-47.6 mL/min) to 58.9 mL/min (0.98 mL/s) (95% CI, 55.6-62.3 mL/min) 2 days after the contrast administration (P&lt;.001).The increase was not significant in the control group (from 42.1 to 44.1 mL/min [0.70 to 0.74 mL/s]; P = .15). The benefit of acetylcysteine was consistent among various patient subgroups and persistent for at least 7 days. There were no major treatment-related adverse events.Conclusion Acetylcysteine protects patients with moderate chronic renal insufficiency from contrast-induced deterioration in renal function after coronary angiographic procedures, with minimal adverse effects and at a low cost.<br /