Browsing by Author "Yap, Glenn P. A."
Now showing 1 - 11 of 11
Results Per Page
Sort Options
Item Anion Binding as a Strategy for the Synthesis of Porous Salts(Chemistry of Materials, 2022-12-27) Antonio, Alexandra M.; Dworzak, Michael R.; Korman, Kyle J.; Yap, Glenn P. A.; Bloch, Eric D.Porous salts have recently emerged as a promising new class of ultratunable permanently microporous solids. These adsorbents, which were first reported as ionic solids based on porous cations and anions, can be isolated from a wide variety of charged, permanently porous coordination cages. A challenge in realizing the full tunability of such systems, however, lies in the fact that the majority of coordination cages for which surface areas have been reported are comprised of charge-balanced inorganic and organic building blocks that result in neutral cages. As such, most reported permanently porous coordination cages cannot be used as reagents in the synthesis of porous salts. Here, we show that the facile reaction of TBAX (TBA+ = tetra-n-butylammonium; X = F– and Cl–) with molybdenum paddlewheel-based coordination cages of the M4L4 and M24L24 lantern and cuboctahedra structure types, respectively, affords charged cages by virtue of coordination of halide anions to the internal and/or external metal sites on these structures, as confirmed by single-crystal X-ray diffraction, X-ray photoelectron spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. At a practical level, the TBAX/cage reactions, which are fully reversible upon isolation of the cage with the appropriate solvent, solubilize otherwise rigorously insoluble cages. This method significantly increases the solution processability of these highly porous solids. Toward the formation of new porous salts, halide binding also serves to incorporate charge on neutral cages and make them amenable to simple salt metathesis reactions to afford new porous salts based on anions and cations with intrinsic porosity. A combination of diffraction methods and a suite of spectroscopic tools confirms speciation of the isolated solids, which represent a new class of highly tunable porous salts. Ultimately, this work represents a roadmap for the preparation of new porous solids and showcases the utility and broad applicability of anion binding as a strategy for the synthesis of porous salts.Item Coordination geometry of lead carboxylates – spectroscopic and crystallographic evidence(Royal Society of Chemistry, 2014-12-14) Catalano, Jaclyn; Murphy, Anna; Yao, Yao; Yap, Glenn P. A.; Zumbulyadis, Nicholas; Centeno, Silvia A.; Dybowski, Cecil; Jaclyn Catalano, Anna Murphy, Yao Yao, Glenn P. A. Yap, Nicholas Zumbulyadis, Silvia A. Centeno and Cecil Dybowski; Catalano, Jaclyn; Murphy, Anna; Yao, Yao; Yap, Glenn P. A.; Dybowski, CecilDespite their versatility, only a few single-crystal X-ray structures of lead carboxylates exist, due to difficulties with solubility. In particular, the structures of long-chain metal carboxylates have not been reported. The lone electron pair in Pb(II) can be stereochemically active or inactive, leading to two types of coordination geometries commonly referred to as hemidirected and holodirected structures, respectively. We report 13C and 207Pb solid-state NMR and infrared spectra for a series of lead carboxylates, ranging from lead hexanoate (C6) to lead hexadecanoate (C18). The lead carboxylates based on consistent NMR parameters can be divided in two groups, shorter-chain (C6, C7, and C8) and longer-chain (C9, C10, C11, C12, C14, C16, and C18) carboxylates. This dichotomy suggests two modes of packing in these solids, one for the short-chain lead carboxylates and one for long-chain lead carboxylates. The consistency of the 13C and 207Pb NMR parameters, as well as the IR data, in each group suggests that each motif represents a structure characteristic of each subgroup. We also report the single-crystal X-ray diffraction structure of lead nonanoate (C9), the first single-crystal structure to have been reported for the longer-chain subgroup. Taken together the evidence suggests that the coordination geometry of C6–C8 lead carboxylates is hemidirected, and that of C9–C14, C16 and C18 lead carboxylates is holodirected.Item Dinuclear copper(I) complexes with N-heterocyclic thione and selone ligands: synthesis, characterization, and electrochemical studies(Royal Society of Chemistry, 2015-08-18) Kimani, Martin M.; Watts, David; Graham, Leigh A.; Rabinovich, Daniel; Yap, Glenn P. A.; Brumaghim, Julia L.; Martin M. Kimani, David Watts, Leigh A. Graham, Daniel Rabinovich, Glenn P. A. Yap and Julia L. Brumaghim; Yap, Glenn P. A.The synthesis, characterization, and structures of a series of homoleptic and heteroleptic copper(I) complexes supported by N-heterocyclic chalcogenone ligands is reported herein. The quasi-reversible Cu(II/I) reduction potentials of these copper complexes with monodentate (dmit or dmise) and/or bidentate (BmmMe, BsemMe, BmeMe, BseeMe) chalcogenone ligands are highly dependent upon the nature and number of the donor groups and can be tuned over a 470 mV range (−369 to 102 mV). Copper–selone complexes have more negative Cu(II/I) reduction potentials relative to their thione analogs by an average of 137 mV, and increasing the number of methylene units linking the heterocyclic rings in the bidentate ligands results in more negative reduction potentials for their copper complexes. This ability to tune the copper reduction potentials over a wide range has potential applications in synthetic and industrial catalysis as well as the understanding of important biological processes such as electron transfer in blue copper proteins and respiration.Item Hydrogen-Bonded Organic Frameworks Based on Endless-Stacked Amides for Iodine Capture and Detection(Advanced Functional Materials, 2023-12-10) Li, Bin; Qiu, Weiguang; Yap, Glenn P. A.; Dory, Yves L.; Claverie, Jerome P.Recently, hydrogen-bonded organic frameworks (HOFs) have emerged as a rapidly advancing class of porous materials with significant potential for applications in the absorption and detection of various chemicals. Here, the unique ability of amide groups to form endless-stacking H-bonds is implemented in the design of HOFs. Starting from benzene-1,3,5-tricarboxamide and amide-containing tribenzocyclynes as foundational building blocks, a diverse range of HOFs featuring 1D, 2D, or 3D hydrogen-bonded frameworks has been synthesized. Among those, all three porous HOFs, HOF_B-Hex, HOF_T-Pr and HOF_T-Hex exhibited permanent porosity, thereby demonstrating the effectiveness of amide-based HOFs strategy. Notably, HOF_T-Hex stands out with a 42% pore volume and an impressive iodine capture efficiency of 6.4 g g−1. The iodine capture capacity is influenced not only by pore volume but also by the presence of accessible π-electrons within the material (i.e., electrons not engaged in a π–π stacking interaction. Furthermore, some of these HOFs exhibited fluorescent responses to iodine positioning them as highly promising materials for both the capture and sensing of iodine.Item Increasing the stability of calixarene-capped porous cages through coordination sphere tuning(Dalton Transactions, 2024-01-05) Dey, Avishek; Dworzak, Michael R.; Korathotage, Kaushalya D. P.; Ghosh, Munmun; Hoq, Jahidul; Montone, Christine M.; Yap, Glenn P. A.; Bloch, Eric D.Chemically and thermally stable permanently porous coordination cages are appealing candidates for separations, catalysis, and as the porous component of new porous liquids. However, many of these applications have not turned to microporous cages as a result of their poor solubility and thermal or hydrolytic stability. Here we describe the design and modular synthesis of iron and cobalt cages where the carboxylate groups of the bridging ligands of well-known calixarene capped coordination cages have been replaced with more basic triazole units. The resultingly higher M–L bond strengths afford highly stable cages that are amenable to modular synthetic approaches and potential functionalization or modification. Owing to the robust nature of these cages, they are highly processable and are isolable in various physical states with tunable porosity depending on the solvation methods used. As the structural integrity of the cages is maintained upon high activation temperatures, apparent losses in porosity can be mediated by resolvation and crystallization or precipitation.Item Isocorrole-Loaded Polymer Nanoparticles for Photothermal Therapy under 980 nm Light Excitation(ACS Omega, 2022-10-18) Marek, Maximilian R. J.; Pham, Trong-Nhan; Wang, Jianxin; Cai, Qiuqi; Yap, Glenn P. A.; Day, Emily S.; Rosenthal, JoelPhotothermal therapy (PTT) is a promising treatment option for diseases, including cancer, arthritis, and periodontitis. Typical photothermal agents (PTAs) absorb light in the near-infrared (NIR)-I region of 650–900 nm with a predominant focus around 800 nm, as these wavelengths are minimally absorbed by water and blood in the tissue. Recently, interest has grown in developing nanomaterials that offer more efficient photothermal conversion and that can be excited by light close to or within the NIR-II window of 1000–1700 nm, which offers less absorption by melanin. Herein, we report on the development of 5,5-diphenyl isocorrole (5-DPIC) complexes containing either Zn(II) or Pd(II) (Zn[5-DPIC] and Pd[5-DPIC], respectively) that absorb strongly across the 850–1000 nm window. We also show that poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with these designer isocorroles exhibit low toxicity toward triple-negative breast cancer (TNBC) cells in the dark but enable efficient heat production and photothermal cell ablation upon excitation with 980 nm light. These materials represent an exciting new platform for 980 nm activated PTT and demonstrate the potential for designer isocorroles to serve as effective PTAs.Item Mechanism-based design of labile precursors for chromium(I) chemistry(Royal Society of Chemistry, 2015-08-27) Akturk, Eser S.; Yap, Glenn P. A.; Theopold, Klaus H.; Eser S. Akturk, Glenn P. A. Yap and Klaus H. Theopold; Akturk, Eser Sahin; Yap, Glenn P. A.; Theopold, Klaus H.Dinitrogen complexes of the type TpR,RCr–N2–CrTpR,R are not the most labile precursors for Cr(I) chemistry, as they are sterically protected from obligatory associative ligand substitution. A mononuclear alkyne complex – TptBu,MeCr(g2-C2(SiMe3)2) – proved to be much more reactive.Item Mirror-plane disorder in a nickel chloride Schiff base complex: a suitable case study for crystallographic instruction(Acta Crystallographica Section C: Structural Chemistry, 2022-01-27) Hsuan, Chang; Chen, Wen-Ching; Shen, Jiun-Shian; Ong, Tiow-Gan; Wang, Vincent C.-C.; Yap, Glenn P. A.The nickel chloride complex of the Schiff base N2,N20-propanediylbis(2,3-butanedione-2-imine-3-oxime), namely, chlorido(3,9-dimethylundeca-3,8-diene-2,10-dione 10-oxime 2-oximato- 4N,N0,N00,N000)nickel(II), [NiCl(C 11 H19 N4 O2 )], at 100 K crystallizes in the orthorhombic space group Cmce. The structure exhibits mirror disorder of the main molecule that is not present in the bromide analogue. The relatively small number of unique reflections in the data set and the disorder imposed by the crystallographic mirror plane present a challenging educational case study.Item A molecular substitutional disorder case study suitable for instruction: L2CrII(THF)/L2[(trimethylsilyl)methyl]CrIII (L is 2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ide)(Acta Crystallographica Section C: Structural Chemistry, 2022-04-06) Salisbury, Brian A.; Young, John F.; Theopold, Klaus H.; Yap, Glenn P. A.A solution of CrII and CrIII complexes, bis(2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ido)(tetrahydrofuran)chromium(II)–bis(2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ido)[(trimethylsilyl)methyl]chromium(III) (0.88/0.12), [Cr(C30H38N3)2(C4H8O)]0.88[Cr(C30H38N3)2(C4H11Si)]0.12 or L2CrII(THF)/L2[(trimethylsilyl)methyl]CrIII (L = 2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ide and THF is tetrahydrofuran), in pentane crystallizes in the monoclinic space group P21/c. The structure obtained shows most of the atoms coincident but with THF disordered with the (trimethylsilyl)methyl ligand. Structures with this disorder, involving more than two or three atoms, seem to appear rarely in the literature; however, in this case, the data set is ideal for the crystallographic instruction of molecular substitution disorder.Item Proline C–H bonds as loci for proline assembly via C–H/O interactions(ChemBioChem, 2022-09-21) Daniecki, Noah J.; Bhatt, Megh R.; Yap, Glenn P. A.; Zondlo, Neal JosephProline residues within proteins lack a traditional hydrogen bond donor. However, the hydrogens of proline are all sterically accessible, with polarized C–H bonds that can be sites for molecular recognition. C–H/O interactions, between proline C–H bonds and oxygen lone pairs, have been previously identified as modes of recognition in proteins. A series of proline derivatives was synthesized, including 4R-hydroxyproline nitrobenzoate methyl ester, acylated on the proline nitrogen with bromoacetyl and glycolyl groups, and Boc-4S-(4-iodophenyl)hydroxyproline methyl amide. All three derivatives exhibited multiple close intermolecular C–H/O interactions in the crystallographic state, with H•••O distances as close as 2.3 Å. These observed distances are well below the 2.72 Å sum of the van der Waals radii of H and O. We further analyzed the role of C–H/O interactions in all previously crystallized derivatives of these amino acids, and found that all 26 structures exhibited close intermolecular C–H/O interactions. Finally, we analyzed all proline residues in the Cambridge Structural Database. The majority of these structures exhibited intermolecular C–H/O interactions at proline C–H bonds, suggesting that C–H/O interactions are an inherent and important mode for recognition of and higher-order assembly at proline residues. Due to steric accessibility and multiple polarized C–H bonds, proline residues are uniquely positioned as sites for binding and recognition via C–H/O interactions.Item Synthesis, Characterization, and Reactivity of Tris(imido)chromium(VI) Complexes(Inorganic Chemistry, 2023-11-27) Wu, Pengcheng; Yap, Glenn P. A.; Theopold, Klaus H.Multiple tris(imido)chromium(VI) complexes, including neutral and ionic compounds, have been synthesized and characterized. (tBuN)2Cr(NHtBu)Cl can be deprotonated by KN(SiMe3)2, yielding K[(tBuN)3CrCl]. This tris(imido) anion undergoes nucleophilic substitution by PPh3 and tBuNH2 to form (tBuN)3Cr(PPh3) and (tBuN)2Cr(NHtBu)2, respectively. (tBuN)2Cr(NHtBu)2 loses one amido proton to form K[(tBuN)3Cr(NHtBu)] upon reaction with KN(SiMe3)2. The imido ligands of K[(tBuN)3CrCl] and (tBuN)3Cr(PPh3) are attacked by the electrophile MeI to produce (tBuN)2Cr(NMetBu)Cl and (tBuN)2Cr(NMetBu)I, respectively. An alternate way to make tris(imido) anions is deprotonation of (tBuN)2Cr(NHtBu)Cl by an alkyl lithium reagent, e.g., Me3SiCH2Li. The resulting Li[(tBuN)3CrCl] was alkylated by a second equivalent of Me3SiCH2Li to form Li[(tBuN)3Cr(CH2SiMe3)]. Reactivity studies of tris(imido) complexes show cycloaddition with PhNCO or CO2 to form metallacycles.