Escaping the Environmental Crises: Online Escape Rooms for Evaluating Student Data Analysis Skills.

Summative lab assessments probe student mastery over concepts, but conventional ones often result in decreased student engagement and confidence. If conventional summative lab assessments are replaced by accessible gamified evaluations, such as online escape rooms, this leads to improved student engagement and confidence. In this work, we adapted two sustainability themed online escape room activities to increase student engagement and confidence in data analyses in Integrated Chemistry I (CHEM 381) over three semesters at CSU, Chico. Over 89.7% of students earned full credit. Further, 80.0% of the written comments included positive feedback. After the online escape room assessments, 60.0% of the students rated their confidence as "high" or "very high" in all categories assessed, compared to 25.6% before the experience. Students found that the online escape room assessments were more engaging than the traditional assessment and increased their confidence as they worked toward solving two sustainability crises and competed for the quickest time to complete the escape rooms.

From n- to p-Type Material: Effect of Metal Ion on Charge Transport in Metal-Organic Materials.

An intriguing new class of two-dimensional (2D) materials based on metal-organic frameworks (MOFs) has recently been developed that displays electrical conductivity, a rarity among these nanoporous materials. The emergence of conducting MOFs raises questions about their fundamental electronic properties, but few studies exist in this regard. Here, we present an integrated theory and experimental investigation to probe the effects of metal substitution on the charge transport properties of M-HITP, where M = Ni or Pt and HITP = 2,3,6,7,10,11-hexaiminotriphenylene. The results show that the identity of the M-HITP majority charge carrier can be changed without intentional introduction of electronically active dopants. We observe that the selection of the metal ion substantially affects charge transport. Using the known structure, Ni-HITP, we synthesized a new amorphous material, a-Pt-HITP, which although amorphous is nevertheless found to be porous upon desolvation. Importantly, this new material exhibits p-type charge transport behavior, unlike Ni-HITP, which displays n-type charge transport. These results demonstrate that both p- and n-type materials can be achieved within the same MOF topology through appropriate choice of the metal ion.

Layer-by-Layer Assembled Films of Perylene Diimide- and Squaraine-Containing Metal-Organic Framework-like Materials: Solar Energy Capture and Directional Energy Transfer.

We demonstrate that thin films of metal-organic framework (MOF)-like materials, containing two perylenediimides (PDICl4, PDIOPh2) and a squaraine dye (S1), can be fabricated by layer-by-layer assembly (LbL). Interestingly, these LbL films absorb across the visible light region (400-750 nm) and facilitate directional energy transfer. Due to the high spectral overlap and oriented transition dipole moments of the donor (PDICl4 and PDIOPh2) and acceptor (S1) components, directional long-range energy transfer from the bluest to reddest absorber was successfully demonstrated in the multicomponent MOF-like films. These findings have significant implications for the development of solar energy conversion devices based on MOFs.

Metal-organic framework materials for light-harvesting and energy transfer.

A critical review of the emerging field of MOFs for photon collection and subsequent energy transfer is presented. Discussed are examples involving MOFs for (a) light harvesting, using (i) MOF-quantum dots and molecular chromophores, (ii) chromophoric MOFs, and (iii) MOFs with light-harvesting properties, and (b) energy transfer, specifically via the (i) Förster energy transfer and (ii) Dexter exchange mechanism.

Post-assembly transformations of porphyrin-containing metal-organic framework (MOF) films fabricated via automated layer-by-layer coordination.

Herein, we demonstrate the robustness of layer-by-layer (LbL)-assembled, pillared-paddlewheel-type MOF films toward conversion to new or modified MOFs via solvent-assisted linker exchange (SALE) and post-assembly linker metalation. Further, we show that LbL synthesis can afford MOFs that have proven inaccessible through other de novo strategies.

Layer-by-layer fabrication of oriented porous thin films based on porphyrin-containing metal-organic frameworks.

We report the synthesis and characterization of two thin films (DA-MOF and L2-MOF) of porphyrin-based MOFs on functionalized surfaces using a layer-by-layer (LbL) approach. Profilometry measurements confirm that the film thickness increases systematically with number of growth cycles. Polarization excitation and fluorescence measurements indicate that the porphyrin units are preferentially oriented, while X-ray reflectivity scans point to periodic ordering. Ellipsometry measurements show that the films are highly porous. Since there are currently few methods capable of yielding microporous MOFs containing accessible free-base porphyrins, it is noteworthy that the LbL growth permits direct MOF incorporation of unmetalated porphyrins. Long-range energy transfer is demonstrated for both MOF films. The findings offer useful insights for subsequent fabrication of MOF-based solar energy conversion devices.