Using nonliving bis(phenoxyimine)titanium catalysts activated by methylaluminoxane (MAO) in the presence of propylene, allyl-terminated syndiotactic polypropylene macromonomers with varying tacticity ([rrrr] = 0.80 and 0.94) and molecular weight (Mn = 3600 and 5600 g/mol) were produced. The end-functionalized polymers were converted to hydroxyl- and subsequently norbornene-terminated macromonomers. Two series of syndiotactic polypropylene comb-polymers were synthesized through metathesis polymerization of the norbornene-functionalized polypropylene. The molecular weight (Mn = 46 000–172 000 g/mol) and polydispersity (Mw/Mn = 1.21–1.89) of the comb polymers was determined by gel permeation chromatography (GPC). Using differential scanning calorimetry (DSC), melting temperature (Tm) and crystallization temperature (Tc) were determined and both were observed to decrease with increasing conversion to poly(macromonomer). To the best of our knowledge, this is the first synthesis of comb-polymers from end-functionalized syndiotactic polypropylene

Using two living nickel α-diimine complexes (rac-1 and rac-4) activated with methylaluminoxane (MAO), isotactic polypropylene (iPP) samples containing five types of regiodefects were synthesized. Both isolated and successive groups of (2,1) and (3,1) enchainments were identified by solution-state 13C NMR spectroscopy. The extended monomer and bulky nature of these defects add some restraints to the crystallinity level that can be achieved in these polymer samples. The complex based on a cumyl-derived ligand, rac-4, produces higher molecular weight iPP with a higher content of bulky defects than rac-1. Melting temperatures and crystallinity levels of rac-4-derived iPP are accordingly lower than the polymers obtained from rac-1. Although the nature of the chain-walking defect is similar to the addition of the ethylene unit, the difference in polymer properties is profound. At equivalent point defects per total monomers (X B), iPP samples with chain-walking defects display lower melting temperatures and much lower degrees of crystallinity than random 1-alkene copolymers, including those with comonomers excluded from the crystal lattice such as the 1-hexene and 1-octene counits. Furthermore, iPP containing (3,1) regiodefects develops significantly higher contents of the γ-polymorph than any other iPP or random copolymer with a matched X B composition. The experimental evidence is consistent with shorter crystallizable sequences for iPP with chain-walking defects based on (3,1) enchainments. Taking crystallizable and noncrystallizable total units as the basis to compute point defects, the properties of (3,1) iPP adhere to the basis of exclusion equilibrium theory, indicating that the defects are random-bulky or generated in a random fashion but of a defined extended/multimonomer nature.

An interdisciplinary laboratory experiment involving second-year undergraduate organic chemistry and introductory inorganic chemistry undergraduate students is described. Organic chemistry students prepare a series of amine-bis(phenols) via a Mannich reaction, and characterize their products using melting point; FTIR; and 1 H, 13 C, DEPT-135, and HSQC NMR experiments. In the inorganic chemistry laboratory, students utilize these amine ligands to prepare a series of octahedral titanium complexes, and characterize the resultant complexes using FTIR, and 1 H, 13 C, DEPT-135, and HSQC NMR spectroscopy. Students are asked to revisit concepts such as the two-and three-dimensional representations of their target molecules and reaction mechanisms throughout both experiments. From these experiments, students gain an appreciation for the multidisciplinary nature of chemistry.

2D NMR spectroscopy techniques are introduced to second-year undergraduate organic chemistry students using a 3 h classroom activity. By first studying simple organic molecules, students are able to build up to solve more complex structures. This classroom activity first utilizes an instructor-guided problem-solving session focused on simple organic molecules (N,N′-dimethylethylene diamine, N,N-dimethylethylene diamine, and 3-(dimethylamino)-1-propylamine). Students then work together in teams to assign a more structurally complex molecule (2,4-dimethylphenol or 2,4-di-tert-butylphenol) using both 1D (1H, 13C, and DEPT-135) and 2D (COSY, HSQC, and HMBC) NMR spectra. By teaching second-year undergraduate students 2D NMR spectroscopy, the techniques are easily revisited in advanced undergraduate courses.

In this organic chemistry laboratory experiment, students are guided through a series of exercises to understand the behavior of compounds during liquid–liquid extraction. Aspects of density, structure, solubility, acid–base theory, and pK a are all incorporated into activities that students complete in groups. After using their initial observations to make predictions about the two colored compounds, nile blue and 2,6-dichloroindophenol, students check the reliability of their predictions by carrying out liquid–liquid extractions of these compounds in the laboratory. The set of exercises culminates in the application of the procedures to a real-world situation.