Normah Awang

Di-n-butyl­bis­[N-(2-meth­oxy­eth­yl)-N-methyl­dithio­carbamato-κ2S,S′]tin(IV): crystal structure and Hirshfeld surface analysis

A skew trapezoidal bipyramidal coordination geometry based on a C2S4 donor set is found in the structure of (C6H5)2Sn[S2CN(Me)CH2CH2OMe]2, with the SnIV atom lying on a mirror plane.

Distinct coordination geometries in bis­[N,N-bis­(2-meth­oxy­eth­yl)di­thio­carbamato-κ2S,S′]di­phenyltin(IV) and bis­[N-(2-meth­oxy­eth­yl)-N-methyl­dithio­carbamato-κ2S,S′]di­phenyl­tin(IV): crystal structures and Hirshfeld surface analysis

Two distinct coordination geometries, each based on a C2S4 donor set, are found in the title compounds, being based on an octahedron in (C6H5)2Sn(S2CN(Me)CH2CH2OMe)2 and a skew trapezoidal bipyramid in (C6H5)2Sn[S2CN(CH2CH2OMe)2]2.

Di-n-butyl­bis­(N-cyclo­hexyl-N-ethyl­dithio­carbamato-κ2S,S′)tin(IV)

The SnIV atom in the title compound, [Sn(C4H9)2(C9H16NS2)2], is chelated by the two dithiocarbamate ions in a six-coordinate skew-trapezoidal-bipyramidal geometry. The two butyl groups are disordered over two positions in a 1:1 ratio.

Di-n-butyl-bis-(N-ethyl-N-phenyl-dithio-carbamato-κS)tin(IV).

The title compound, [Sn(C4H9)2(C9H10NS2)2], features a tetrahedrally coordinated SnIV atom; the dithiocarbamate ligands coordinate in a monodentate fashion, accompanied by two n-butyl chains. The non-coordinating thione S atoms are each proximate to the SnIV atom [3.0136 (7) and 2.9865 (8) Å], giving rise to distortions from the ideal geometry as evident in the wide C—Sn—C bond angle of 139.06 (12) °. In the crystal, C—H⋯S interactions lead to the formation of a linear supramolecular chain along the b axis. The chains are aligned into layers by C—H⋯π interactions, and the layers stack along [001]. One of the ethyl groups is statistically disordered over two sets of sites.

Crystal structures and Hirshfeld surface analyses of bis­[N,N-bis­(2-meth­oxy­eth­yl)di­thio­carbamato-κ2S,S′]di-n-butyl­tin(IV) and [N-(2-meth­oxy­eth­yl)-N-methyl­dithio­carbamato-κ2S,S′]tri­phenyl­tin(IV)

The coordination geometry in (n-Bu)2Sn[S2CN(CH2CH2OCH3)2]2, (I), is based on a skewed trapezoidal bipyramid, while that in (C6H5)3Sn[S2CN(CH3)CH2CH2OCH3], (II), is based on a tetrahedron. In the crystal of (I), supramolecular layers parallel to (10-1) are sustained by methylene-C—H⋯O(methoxy) interactions, while in (II), centrosymmetric dimers are formed via pairwise weak phenyl-C—H⋯π(phenyl) contacts.

Exposure Assessment of Formaldehyde and its Symptoms among Anatomy Laboratory Workers and Medical Students

Formaldehyde has commonly been used as an embalming agent in the anatomy laboratory besides being used during production of wood, resins and plastics. This current study involved the measurement of formaldehyde exposure level among anatomy laboratory workers and medical students in anatomy laboratory using the NIOSH 2541 method. The study determined the symptoms resulted from formaldehyde exposure using self-reported symptom questionnaire that has been modified. Mean area concentration of formaldehyde 8 h TWA in the dissection hall and specimen preparation laboratory were 0.1±0.03 and 0.17±0.04 ppm, respectively. Both of these formaldehyde concentrations were below the ceiling limit of 0.30 ppm. Statistically, there was no significant difference between the formaldehyde concentration in the dissection hall and specimen preparation laboratory. The personal exposure 15 min STEL formaldehyde concentration was 2.30±1.53 ppm and it was higher than 15 min STEL of 2 ppm. Results from the anatomy laboratory workers and medical students reported through the self-reported symptom questionnaires revealed that the most common symptoms they experienced during working hour and off working hour where eye and nose irritations, which are 71.3%, 57.5 and 4.6, 8%, respectively. In conclusion, the personal exposure 15 min STEL exceeded the US OSHA standard. Even though the formaldehyde concentration for the area was under the limit, still there were risks to develop an adverse health effect.

(N-Ethyl-N-phenyldithiocarbamato-κS)-triphenyltin(IV)

The title compound, [Sn(C6H5)3(C9H10NS2)], has two independent molecules in the asymmetric unit and each features a tetrahedrally coordinated SnIV atom as the dithiocarbamate ligand coordinates in a monodentate fashion. As the non-coordinating thione S atom is proximate to the Sn atom [Sn⋯S(thione) = 3.1477 (6) and 2.9970 (5) Å for the independent molecules], distortions from the ideal geometry are evident [the widest angle being 120.48 (5)°]. The most notable feature of the crystal packing is the formation of C—H⋯π interactions that lead to the formation of supramolecular layers parallel to (2).

(N-Butyl-N-phenyl­dithio­carbamato-κS)triphenyl­tin(IV)

The title compound, [Sn(C6H5)3(C11H14NS2)], features a tetrahedrally coordinated Sn atom, as the dithiocarbamate ligand coordinates in a monodentate fashion. Due to the proximity of the non-coordinating thione S atom, distortions from ideal tetrahedral geometry about the metal atom are evident with the widest C—Sn—S angle being 117.26 (5)°. In the crystal, molecules are linked by C—H⋯S interactions, which generate helical supramolecular chains along the b axis.

(N-sec-Butyl-N-n-propyl­dithio­carbamato-κ2S,S′)triphenyl­tin(IV)

The Sn atom in the title compound, [Sn(C6H5)3(C8H16NS2)], is pentacoordinated by two S atoms, derived from an asymmetrically coordinating dithiocarbamate ligand, and three ipso-C atoms. The coordination geometry is intermediate between square-pyramidal and trigonal-bipyramidal, with a leaning towards the latter. The presence of close intramolecular C—H⋯S contacts preclude the S atoms from forming significant intermolecular interactions. Rather, molecules are consolidated in the crystal structure by C—H⋯π interactions.

Crystal structures and Hirshfeld surface analyses of (N-hexyl-N-methyl­dithio­carbamato-κ2S,S′)triphenyl­tin(IV) and [N-methyl-N-(2-phenyl­ethyl)­dithio­carbamato-κ2S,S′]tri­phenyl­tin(IV)

The metal coordination geometry in each of the title molecules, [Sn(C6H5)3(C8H16NS2)] (I) and [Sn(C6H5)3(C10H12NOS2)] (II), is based on a heavily distorted tetrahedron owing to the asymmetric mode of coordination of the dithiocarbamate ligand. The persence of C—H⋯π(phenyl) interactions in the crystals lead to dimeric aggregates in (I) and supramolecular chains (II).