Metal acetylacetonate–amine and metal nitrate–amine complexes as low‐emission catalysts for rigid polyurethane foam preparation

Abstract

Six metal-amine complexes, Cu(acac) 2 (trien), Zn(acac) 2 (en), Zn(acac) 2 (trien), Cu(NO 3 ) 2 (en) 2 , Cu(NO 3 ) 2 (trien), and Cu(NO 3 ) 2 (tetraen), are synthesized from metal acetylacetonates [M(acac) 2 , where M 5 Cu and Zn] or metal nitrate [M(NO 3 ) 2 , where M 5 Cu] and aliphatic amines (en 5 ethylenediamine, trien 5 triethylenetetramine, and tetraen 5 tetraethylenepentamine). These metal-amine complexes can be used as catalysts in the preparation of rigid polyurethane (RPUR) foams. All metal-amine complexes emit very weak odor when compared with N,N-dimethylcyclohexylamine (DMCHA), which is a commercial catalyst commonly used in the preparation of RPUR foams. DMCHA emits very strong amine odor that affects working environment in RPUR foam processing. Among all metal complexes, Cu(acac) 2 (trien) has the highest catalytic activity. In comparison with DMCHA, Cu(acac) 2 (trien) shows slightly higher catalytic activity in gelling reaction but lower catalytic activity in blowing reaction. RPUR foam prepared from Cu(acac) 2 (trien) has lower density and compressive strength than that prepared from DMCHA. V C 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42332.

Deciphering the mechanism behind efficient enantioselective ethylation with thiazolidine‐based amino alcohols

“…The preservation of the amine protons in zinc complexes is widely acknowledged in the literature, both in enantioselective alkylation studies and in the synthesis of coordination complexes. [ 89–92 ]…”

“…The preservation of the amine protons in zinc complexes is widely acknowledged in the literature, both in enantioselective alkylation studies and in the synthesis of coordination complexes. [89][90][91][92] One point that should be stressed is that because the zinc atom that is not involved in the alkyl group transfer, when linked to four different groups, can be considered chiral and adopts an approximately tetrahedral geometry. The coordination of the aldehyde to either face of the zinc atom leads to a completely different set of arrangements.…”

Tuning Branching in Ceria Nanocrystals

“…Upon addition of the cerium salt to the ODE solution containing OAm and heating to 80 °C, a cerium-OAm complex is formed. 63 This complex started to decompose at around 200 °C to produce quasi-spherical CeO2 NCs with a ca. 90% material yield (Figure 1a).…”

Ligand Conversion in Nanocrystal Synthesis: The Oxidation of Alkylamines to Fatty Acids by Nitrate

“…In a typical synthesis, Ce(NO 3 ) 3 ·6H 2 O is dissolved under vacuum in oleylamine and 1-octadecene forming a complex, [Ce(RNH 2 ) n (NO 3 ) 3 ]. 4 , 43 Upon heating, this complex decomposes, yielding CeO 2- x NCs. …”