A relative ability of industrial samples of four phosphorus-free polymers (polyaspartate (PASP); polyepoxysuccinate (PESA); polyacrylic acid sodium salt (PAAS); copolymer of maleic and acrylic acid (MA-AA)) and of three phosphonates (aminotris(methylenephosphonic acid), ATMP; 1-hydroxyethane-1,1-bis(phosphonic acid), HEDP; phosphonobutane-1,2,4-tricarboxylic acid, PBTC) to inhibit calcium sulfate precipitation is studied following the NACE Standard along with dynamic light scattering (DLS), scanning electron microscopy (SEM), and X-ray diffraction (XRD) technique. For the 0.5 mg·dm−3dosage, the following efficiency ranking was found:MA-AA~ATMP>PESA (400–1500 Da)>PASP (1000–5000 Da)≫PAAS (3000–5000 Da)~PBTC~HEDP. The isolated crystals are identified as gypsum. SEM images for PESA, PASP, PAAS, and HEDP and for a blank sample indicated the needle-like crystal morphology. Surprisingly, the least effective reagent PBTC revealed quite a different behavior, changing the morphology of gypsum crystals to an irregular shape. The DLS experiments exhibited a formation of 300 to 700 nm diameter particles with negativeζ-potential around −2 mV for all reagents.Although suchζ-potential values are not capable of providing colloidal stability, all three phosphonates demonstrate significant gypsum particles stabilization relative to a blank experiment.

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The supramolecular dimeric complex [(μ-oxo)bis(tetra-15-crown-5-phthalocyaninato)(nicotinato)aluminum(III)]tetra(rubidium) bis(nicotinate) was prepared by addition of an excess of a methanol solution of rubidium nicotinate to a chloroform solution of the aluminum crown-phthalocyaninate, [(HO)Al(15C5)Pc]. A single-crystal X-ray diffraction study of {[Rb(NicAl(15C5)Pc)(μ-O)](Nic)}·2.36HNic·11HO demonstrated that two molecules of the aluminum crown-phthalocyaninate nicotinate are connected through an Al-O-Al bridge supported by sandwiching of crown ether moieties by Rb cations.

An original method based on metal-free ligand and lanthanide acetate direct interaction in the presence of a strong organic base (DBU) is used to prepare sandwich-type gadolinium and ytterbium crown-ether substituted phthalocyanines bis[4,5,4′,5′,4″,5″,4‴,5‴-tetrakis(1,4,7,10,13-pentaoxatridecamethylene)phthalocyaninato]gadolinium (ytterbium) and tris[4,5,4′,5′,4″,5″,4‴-,5‴-tetrakis(1,4,7,10,13-pentaoxatridecamethylene)phthalocyaninato]digadolinium (ytterbium) which are characterized by MALDI-TOF mass spectrometry and UV-vis spectroscopy.

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