Zaštitna aluminijska prevlaka izvedena izravno u ljevačkom kalupu na čeliku otpornom prema puzanju

The structure of coatings and their ability to protect the castings made of G-X25NiCrSi 36-17 (DIN 17006) cast steel against carburization have been described. Al-Cu and Al-Si protective coatings, produced directly in a casting mould, have a considerable thickness (400 - 2000 µm), and complex multiphase structure. Its main structural constituents are: (Fe, Ni, Cr), (Fe, Ni, Cr), Al(Ni, Fe), carbides M23C6 and M7C3. In Al-Si ferritic coatings are also present: (Ni, Fe), (Fe, Al, Ni, Cr) and (Cr, Si)3Ni2Si. Carburisation changes substantially the structure of coatings, what results in an increase of the amount of (Fe, Ni, Cr) or (Ni, Fe) and carbides, and a decrease of the amount of (Fe, Ni, Cr) and Al(Ni, Fe). Apart from above mentioned changes, the investigated coatings reduce the carbon diffusion by 20 - 65 % Al-Cu, about 55 % Al-Si (austenitic), and 75 % Al-Si (ferritic), so they can provide a temporary protection against high-temperature corrosion.U radu je opisana struktura prevlaka i njihova sposobnost lijevanja od G-X25NiCrSi 36-17 (DIN 17006) u svrhu zaštite protiv naugljičavanja. Zaštitne prevlake Al-Cu i Al-Si, napravljene izravno u ljevačkom kalupu, imaju znatnu debljinu (400 - 2000 µm) i složenu multifaznu strukturu. Glavni strukturni element su: g(Fe, Ni, Cr), a(Fe, Ni, Cr), bAl(Ni, Fe), karbidi M23C6 i M7C3. U feritnim prevlakama Al-Si prisutni su i: g(Ni, Fe), a(Fe, Al, Ni, Cr) i (Cr, S)3Ni2Si. Naugljičavanje mijenja suštinu strukture prevalaka, a to dovodi do povećanja količine g(Fe, Ni, Cr) ili g(Ni, Fe) i karbida, a smanjuje količinu a(Fe, Ni, Cr) i bAl(Ni, Fe). Neovisno o gore spomenutim promjenama prevlake smanjuju difuziju ugljika za 20-60 % Al-Cu, oko 55 % Al-Si (austenitni) i 75 % Al-Si (feritni) pa mogu osigurati privremenu zaštitu protiv korozije na visokoj temperaturi

2-Chloro-N-[4-chloro-2-(2-chloro­benzo­yl)phen­yl]acetamide

In the title compound, C15H10Cl3NO2, an intra­molecular N—H⋯O hydrogen bond forms a six-membered ring and enforces an almost coplanar conformation for the acetamido group, the central benzene ring and the bridging carbonyl C—C(=O)—C group: the dihedral angles between the benzene ring and the acetamide and carbonyl C—C(=O)—C planes are 7.06 (11) and 7.17 (12)°, respectively. The dihedral angle between the two benzene rings is 67.43 (9)°. Because a strong hydrogen-bond donor is involved in the intra­molecular inter­action, the crystal packing is determined by weak C—H⋯O and C—H⋯Cl inter­actions

Tramadolium picrate

In the title salt {systematic name: [2-hy­droxy-3-(3-meth­oxy­phen­yl)cyclo­hexyl­meth­yl]dimethyl­aza­nium 2,4,6-trinitro­phenol­ate}, C16H26NO2 +·C6H2N3O7 −, the cation is protonated at the N atom. The cyclo­hexane ring adopts a chair conformation with the hy­droxy substituent in an axial position. In the crystal, O—H⋯O and N—H⋯O hydrogen bonds link the cations and anions into supra­molecular chains along [100]

(1RS,6SR)-Ethyl 4,6-bis­(4-fluoro­phen­yl)-2-oxocyclo­hex-3-ene-1-carboxyl­ate

In the crystal structure of the title compound, C21H18F2O3, the cyclo­hexene ring has a slightly distorted sofa conformation; the two benzene rings are inclined by 76.27 (8)° and their planes make dihedral angles of 16.65 (10) and 67.53 (7)° with the approximately planar part of the cyclo­hexenone ring [maximum deviation 0.044 (2) Å, while the sixth atom is displaced by 0.648 (3) Å from this plane]. In the crystal, weak inter­molecular C—H⋯O, C—H⋯F and C—H⋯π inter­actions join mol­ecules into a three-dimensional structure

(1RS,6SR)-Ethyl 4-(4-chloro­phen­yl)-6-(4-fluoro­phen­yl)-2-oxocyclo­hex-3-ene-1-carboxyl­ate toluene hemisolvate

In the crystal structure of the title compound, C21H18ClFO3·0.5C7H8, the toluene solvent mol­ecules occupy special positions on centres of symmetry, and consequently are disordered across this site. The cyclo­hexene ring has a slightly distorted sofa conformation; the two benzene rings are inclined by 72.90 (7)° and their planes make dihedral angles of 30.09 (10) (chloro­phen­yl) and 88.13 (6)° (fluoro­phen­yl) with the approximately planar part of the cyclo­hexenone ring [maximum deviation from plane through five atoms is 0.030 (2) Å, the sixth atom is 0.672 (3)Å out of this plane]. Weak inter­molecular C—H⋯O and C—H⋯X (X = F, Cl) inter­actions join mol­ecules into a three-dimensional structure. Also, a relatively short and directional C—Cl⋯F—C contact is observed [Cl⋯F = 3.119 (2) Å, C—Cl⋯F = 157.5 (2)° and C—F⋯Cl 108.3 (2)°]. The solvent mol­ecules fill the voids in the crystal structure and are kept there by relatively short and directional C—H⋯π inter­actions

1-Methyl­piperazine-1,4-diium dipicrate

In the crystal structure of the title compound [systematic name: 1-methyl­piperazine-1,4-diium bis­(2,4,6-trinitro­phen­ol­ate)], C5H14N2 2+·2C6H2N3O7 −, the ionic components are connected by relatively strong N—H⋯O hydrogen bonds into centrosymmetric six-membered conglomerates, which comprise two dications and four anions. Besides Coulombic inter­actions, only weak C—H⋯O inter­actions and some stacking between picrates (separation between the planes of ca. 3.4 Å but only a small overlapping) can be identified between these ‘building blocks’ of the crystal structure. The piperazine ring adopts a chair conformation with the methyl substituent in the equatorial position. In the picrate anions, the twist angles of the nitro groups depend on their positions relative to the phenolate O atom: it is much smaller for the NO2 groups para to the C—O− group [15.23 (9)and 3.92 (14)°] than for the groups in the ortho positions [28.76 (13)–39.84 (11)°]

(2E)-1-(4-Bromo­phen­yl)-3-(4-fluoro­phen­yl)prop-2-en-1-one

The title compound, C15H10BrFO, is isostructural with (2E)-1-(4-chloro­phen­yl)-3-(4-fluoro­phen­yl)prop-2-en-1-one [Qiu et al. (2006 ▶). Acta Cryst. E62, o3525–o3526], but the structures of other dihalogen analogues, without fluorine, are different, although they are also isostructural within the series. The mol­ecule is approximately flat, the dihedral angle between the ring planes being 8.49 (13)°. In the crystal structure, inter­molecular C—H⋯O, C—H⋯F and C—H⋯Br hydrogen bonds link mol­ecules into V-shaped ribbons running parallel to [101] and stacked with an inter­planar distance of approximately 3.53 Å (centroid–vcentroid distance = 3.857 Å).

(E)-3-(4-Chloro­phen­yl)-1-(1-naphth­yl)prop-2-en-1-one

In the title compound, C19H13ClO, the benzene ring and the naphthalene system, are twisted by 12.3 (3) and 36.1 (2)°, respectively, and in opposite directions with respect to the central propenone bridge. The bond-angle pattern within the benzene ring is influence by both substituents; these influences are almost additive. In the crystal, the molecules are linked by C—H⋯O and C—H⋯Cl inter­actions

(1RS,6SR)-Ethyl 4-(2,4-dichloro­phen­yl)-6-(4-fluoro­phen­yl)-2-oxocyclo­hex-3-ene-1-carboxyl­ate

There are two symmetry-independent mol­ecules in the asymmetric unit of the title compound, C21H17Cl2FO3. Both these mol­ecules are very similar: the normal probability plots for bond lengths, angles and even for torsion angles show that the differences are of a statistical nature. A pseudocentre of symmetry is located between the symmetry-independent mol­ecules at [0.245 (1), 0.535 (19), 0.909 (1)]. The cyclo­hexene rings have slightly distorted sofa conformations in both mol­ecules and the two benzene rings are inclined by dihedral angles of 61.33 (14) and 62.85 (14)°. In the crystal, relatively short inter­molecular C—H⋯O inter­actions join mol­ecules into homomolecular (i.e. ⋯AAA⋯ and ⋯BBB⋯) chains along the b axis. These chains are inter­connected by further heteromolecular C—H⋯O inter­actions