mof_synthesis_qa.csv

Question,Option_A,Option_B,Option_C,Option_D,Option_E,Answer,Domain,Difficulty,Type,Task
What temperature range was used for solvothermal synthesis of ZIF-8? ,-30°C to 0°C,0°C to 20°C ,20°C to 200°C  ,200°C to 500°C , 500°C to 1000°C,C,Materials,Easy,Basic,MOF Synthesis Q&A
Which of the following statements is true about the different types of MOF synthesis ?," In solvothermal synthesis the autoclave is typically filled ≤ 70 % to manage pressure buildup, and a perfectly transparent precursor solution is essential to obtain crystalline product.","Microwave synthesis allows for significantly shorter reaction times, with MOF crystals sometimes forming within just a few minutes but are usually smaller than those from conventional solvothermal routes.",Electrochemical MOF synthesis relies on anodic metal dissolution; for that reason noble‑metal electrodes such as platinum are preferred since they dissolve readily under mild potentials., In neat mechanochemical (ball‑milling) synthesis a ≥ 50 % stoichiometric excess of organic linker is required to act simultaneously as grinding aid and pH modulator.,"During MOF chemical‑vapor deposition on wafers the reactor must be continuously purged with dry N₂ or Ar, because trace H₂O in air passivates the surface and prevents framework growth.",B,Materials,Easy,Basic,MOF Synthesis Q&A
"Which of the following modulators is most commonly used to synthesize aluminum carboxylate-based metal-organic frameworks in aqueous solutions, featuring infinite one-dimensional (1D) chains of parallel AlO₆ octahedra as secondary building units?",Ammonia,Sodium hydroxide,Trifluoracetic acid,Acetic acid,Triethylamine,B,Materials,Easy,Basic,MOF Synthesis Q&A
Which of the following size ranges most closely matches the dimensions of metal–organic‑framework single crystals typically selected for single‑crystal X‑ray diffraction experiments? ,10 – 50 nm,50 – 500 nm, 5 – 30 µm,50 – 300 µm,1 – 5 mm,D,Materials,Easy,Basic,MOF Synthesis Q&A
Which synthetic strategy is generally considered the most reliable for producing nano‑sized (≤ 200 nm) three‑dimensional MOF crystals with a narrow size distribution and high phase purity? ,Conventional solvothermal crystallisation in DMF /H₂O with monotopic‑acid modulators for 24 h at 120 °C," Continuous‑flow micro‑reactor synthesis under super‑critical ethanol (≥ 260 °C, 85 bar) with residence times of 2–5 min","Microwave‑assisted solvothermal heating in sealed vessels (power‑modulated ramp to 140–180 °C in ≤ 60 s, hold ≤ 10 min)","High‑energy planetary ball‑milling of reagents (600 rpm, 30 min) followed by sealed‑tube aging at 100 °C for 48 h",Low‑frequency (40 kHz) bath sonochemistry in N‑methyl‑2‑pyrrolidone for 2 h at 70 °C,C,Materials,Easy,Basic,MOF Synthesis Q&A
"When two or more imidazolate‑type linkers are co‑incorporated into a zeolitic imidazolate framework, which of the following framework topologies is most frequently obtained? ",pcu,qtz,sod,bor,dia,C,Materials,Easy,Basic,MOF Synthesis Q&A
"A research team is synthesizing an aluminum-based MOF using a 4,4′,4′′-Benzene-1,3,5-triyl-tris-(benzoate) linker, denoted as BTB, and explores different parameters to maximize both yield and crystal size. They find that at temperatures below 120°C, yield is ≤15%, while at 140°C, yield is 80%. A BTB:Al ratio of 3:4 increases yield by 10% over 2:1. Using a modulator of formic acid:water at 1:1 doubles the crystal size without changing yield, while a 4:1 ratio decreases crystal size by 30%. Reaction times ≥72h do not affect yield or size. Which of the following recipes maximizes both yield and crystal size? ","2:1 BTB:Al, pure formic acid, 140°C, 72h","3:4 BTB:Al, formic acid:water 1:1, 140°C, 72h","3:4 BTB:Al, formic acid:water 4:1, 140°C, 72h","4:1 BTB:Al, pure formic acid, 130°C, 72h","3:4 BTB:Al, pure formic acid, 120°C, 96h",B,Materials,Medium,Advanced Reasoning,MOF Synthesis Q&A
"A MOF shows signs of hydrolytic instability in water. To investigate the role of formate groups, researchers perform the following: (i) TGA shows decomposition starts at 300°C; (ii) PXRD after water exposure shows a broad halo; (iii) 1H NMR of a D2O/NaOD solution of the MOF shows a single peak at 8.5 ppm, matching formate in the literature; (iv) CHNS analysis shows high C and H but low N and S. Which observation most directly supports the hypothesis that formate groups cause water instability? ",Observation (i),Observation (ii),Observation (iii),Observation (iv),None of the above,C,Materials,Hard,Basic,MOF Synthesis Q&A
"A BET plot for nitrogen adsorption on 0.200 g of the MOF gives a straight line between P/P₀ = 0.05 and 0.30 with slope = 12.0 (g STP cm³)⁻¹ and intercept = 0.60 (g STP cm³)⁻¹; taking the cross‑sectional area of N₂ as 0.162 nm² and using 22 414 cm³ mol⁻¹ at STP, which is closest to the calculated specific surface area? ",350 m² g⁻¹,720 m² g⁻¹,1 200 m² g⁻¹, 1 700 m² g⁻¹,2 400 m² g⁻¹,A,Materials,Medium,Advanced Reasoning,MOF Synthesis Q&A
"Thermogravimetric analysis of the activated MOF shows 3.5 % mass loss up to 120 °C, another 12 % between 120 °C and 300 °C, a plateau to 450 °C, then a sharp 45 % drop ending at 630 °C, after which mass is constant; differential scanning calorimetry records an endotherm peaking at 110 °C and an exotherm peaking at 610 °C; which interpretation best matches these data? ","The 3.5 % loss is physisorbed water, the 12 % is coordinated DMF, and the 45 % drop with exotherm is framework combustion","All mass lost below 300 °C is framework collapse, and the exotherm is solvent evaporation","The initial 3.5 % is coordinated formic acid, the 12 % is linker decomposition, and the 45 % is residual water removal","The 3.5 % is adsorbed nitrogen, the 12 % is BTB linker loss, and the 45 % is aluminum oxide formation without combustion",The exotherm at 610 °C proves the sample never contained solvent—only oxidation of the pan,A,Materials,Medium,Advanced Reasoning,MOF Synthesis Q&A
"Which structural modification to the reference linker (O=C(O)c1ccc(cc1)C(=O)O, terephthalate) is most likely to increase both the pore volume of a framework and its framework CO2 uptake? ",NC1=CC(C(O)=O)=CC=C1C(O)=O,O=C(C1=CC2=C(C=C(C(O)=O)C=C2)C=C1)O,NCC1=CC(C(O)=O)=CC(CN)=C1C2=CC=C(C(O)=O)C=C2,NC(C(N)=C1)=CC2=C1C(C(O)=O)=CC=C2C(O)=O ,NC(C(N)=C1)=CC2=C1C(C(O)=O)=CC=C2C(O)=O ,E,Materials,Hard,Basic,MOF Synthesis Q&A
Which of the following linker may react with Y(NO3)3 to form MOF with permanent porosity?,ONC(C1=CC=C(C2=CC=C(C(NO)=O)C=C2)C=C1)=O,O=C(C1=CC=C(C2=CC=CC=C2)C=C1)O,C1(C=NN2)=C2C=CC=C1,OC1=C2C(C=CC=C2)=C(C=CC3=C(C=CC=C4)C4=C(O)C=C3)C=C1,NC1=CC2=C(/C=C3N=C(/C=C(C4=C/5C=C(N)C=C4)\NC5=C/6)C7=C\3C=CC=C7)NC(/C=C8C9=C(C=CC=C9)C6=N/8)=C2C=C1,A,Materials,Hard,Basic,MOF Synthesis Q&A
"A layered MOF is assembled from: (i) a hexanuclear {Re₃Br₃(CO)₃} cluster that behaves as a 6‑connected planar node (all 60° angles), and (ii) a trigonal organic linker that bridges three different clusters in the same plane (3‑connected node).If no other nodes are present, what is the resulting overall topological symbol for the 2‑D net?","hcb (6,3‑net)","sql (4,4‑net)",kgd (Kagomé‑dual) ,"hxl (3,6‑net)","fes (3,4‑connected net)",C,Materials,Hard,Basic,MOF Synthesis Q&A
"You create two isostructural sql-layer MOFs with paddlewheel Cu₂ units and a linear 4,4′-bipyridyl-type ligand. First, sample X is crystallized from neat DMF; no guest fits inside the 17 × 17 Å squares. On the other hand, sample Y is crystallized from DMF with o-xylene, which enters and fills the grid cavities. Both use identical stoichiometry and conditions, except for the o-xylene. What is the likely structural difference between Sample X and Sample Y? ",X and Y are both non-interpenetrated because sql nets never interpenetrate,X is non-interpenetrated; Y becomes doubly interpenetrated due to guest templating,X is triply interpenetrated; Y is non-interpenetrated because guests block threading,"Both are triply interpenetrated, but Y shows expanded interlayer spacing",X converts to a kgd net while Y retains sql topology ,C,Materials,Hard,Advanced Reasoning,MOF Synthesis Q&A
"A research team replaces ligand L1 (rigid 1,4-bis(4-pyridyl)benzene) with L2 (its fluorinated, methylene-linked analogue: 1,4-bis(4-pyridylmethyl)-2,3,5,6-tetrafluorobenzene) in reactions with Cd(NO3)2. Note that, with L1, the product is a 1-D ladder-like coordination polymer. While with L2, the product is a triply interpenetrated brick-wall (6,3) 2-D layer. What is the most plausible reason for this change in network topology? ","Fluorination of L2 enforces meridional binding, generating a T-shaped Cd node",Fluorination alters Cd²⁺ coordination from octahedral to tetrahedral,"L2 is shorter than L1, preventing sql net formation","The –CH₂– spacers in L2 provide torsional flexibility, enabling brick-wall net","The electron-withdrawing groups raise pH, favoring nitrate bridging ",D,Materials,Medium,Advanced Reasoning,MOF Synthesis Q&A
Which of the following linkers is most likely to assemble into an aluminum-based MOF with the highest water uptake at 30% relative humidity (RH)? ,O=C(C1=CC(/C=C/C(O)=O)=NN1)O ,O=C(C1=NC(C(O)=O)=NN1)O,O=C(C1=CC(C=C(C(O)=O)C=C2)=C2C1)O,NC(/C(N)=C/C(O)=O)=C\C(O)=O,O=C(C1=CC=C(C2=CC=C(C(O)=O)O2)O1)O,A,Materials,Hard,Basic,MOF Synthesis Q&A
"Which of the following molecules is least likely to act as a viable linker for forming a MOF due to geometrical structure and poor connectivity with typical metal centers such as iron, zinc, zirconium, or aluminum? ",O=P(C1=CC2=C(C=C1)C=C(P(O[O])=O)C=C2)O[O],O=C(C(C=C1)=CC=C1C2=CC=NC=C2)O,OC1=CC2=C(C=C1O)C3=C4C(C(C=C(O)C(O)=C5)=C5C=C4)=C6C(C(C=C(O)C(O)=C7)=C7C=C6)=C3C=C2,OC1=CC2=C(C=C1O)C3=C4C(C(C=C(O)C(O)=C5)=C5C=C4)=C6C(C(C=C(O)C(O)=C7)=C7C=C6)=C3C=C2,O=C(C1=COC=C1C(O)=O)O,E,Materials,Hard,Basic,MOF Synthesis Q&A
"Consider a MOF constructed from tetrahedral Zn₄O clusters, where each cluster is connected to 6 linear dicarboxylate linkers (forming connections along the x, y, and z axes). The resulting framework is an extended 3D network (not just layered). Which of the following best describes the topology of this MOF structure? ",3D primitive cubic net (pcu topology) with each node 6-connected,3D diamondoid network (dia topology) with each node 4-connected ,2D square lattice layer (sql topology) extending in two dimensions only,1D one-dimensional coordination polymer chain,3D kagome net composed of tri-connected nodes (kgm topology),A,Materials,Medium,Basic,MOF Synthesis Q&A
"Researchers attempt to increase a MOF’s pore size by using much longer organic linkers in an isoreticular series, but they observe that the framework tends to form interpenetrated (catenated) structures – i.e., two identical networks entangled within the same crystal – which reduces the accessible porosity. Which strategy would most likely help prevent such interpenetration, maintaining a single open network despite the extended linker length? ",Using a very low concentration of reactants so that only one network can form, Shortening the linker again to make the pores smaller ,Introducing bulky substituents on the linker (steric hindrance) to occupy space and deter a second framework from threading through ,Lowering the metal coordination number by choosing a different metal to reduce framework connectivity,Performing the synthesis at much higher temperature to favor a kinetically trapped phase ,C,Materials,Easy,Advanced Reasoning,MOF Synthesis Q&A
"Metal ions in MOFs exhibit distinct coordination preferences and connectivity. For example, Cu(II) often forms a dinuclear “paddlewheel” node (Cu₂-carboxylate) where each Cu₂ cluster is bridged by four carboxylate linkers, whereas Zr(IV) tends to form hexanuclear clusters with high connectivity (as in UiO-type MOFs). Which of the following statements about metal node behavior in MOFs is correct? ","Copper(II) typically forms paddlewheel SBUs where two Cu centers are bridged by four carboxylate groups, yielding a 4-connected node in frameworks like HKUST-1","Zirconium(IV) nodes in MOFs usually prefer only 4-coordinate tetrahedral geometry, limiting them to low connectivity frameworks",Octahedral Zn₄O clusters (as in MOF-5) act as 4-connected nodes because each of the four Zn atoms binds one linker,"Fe(III) cannot form multinuclear cluster nodes in MOFs due to its high charge, so it only appears as isolated single-metal nodes","Ag(I) typically yields 10+-connected symmetric clusters in MOFs, accounting for its propensity to form super-stable networks",A,Materials,Hard,Basic,MOF Synthesis Q&A
"In MOF synthesis, sometimes an extra “template” guest molecule is used to direct the assembly of the framework, analogous to how structure-directing agents are used in zeolite synthesis. Such a template often occupies space in the pores during crystallization and is removed afterward, allowing the desired open framework to form. Which of the following scenarios is an example of a template-directed MOF synthesis? ","Adding a bulky amine (or quaternary ammonium cation) to the solvothermal reaction that fills the pores during growth, enabling formation of a framework that would otherwise collapse or form a different structure (the amine is later washed out)",Using an excess of linker molecules so that some linkers remain uncoordinated in the pores as placeholders during synthesis ,"Adding a modulator (like acetic acid) that competes with the linker for metal coordination, slowing down crystal growth",Carrying out the MOF reaction under inert gas to prevent oxidation of the metal centers during crystallization,"Employing a high-boiling solvent (e.g., DEF) solely to increase solubility of reactants, without any specific guest species present in the pores ",A,Materials,Hard,Basic,MOF Synthesis Q&A
The practical use of MOFs depends strongly on properties like gas adsorption capacity and stability to water or heat. Which of the following statements about MOF physical properties is true? ,"Interpenetrated MOFs usually have higher accessible surface area and gas uptake than their non-interpenetrated (single-network) counterparts, since the second network provides additional adsorption sites","Zirconium-carboxylate frameworks (e.g., UiO-66 series) generally exhibit superior water and thermal stability compared to many Zn(II) or Cu(II) based MOFs, owing to the stronger Zr–O coordination bonds and robust cluster nodes","Most MOF structures irreversibly collapse upon removal of guest solvents, so gas uptake is only possible if the MOF stays solvated","Flexible “breathing” MOFs that change pore shape upon adsorption show identical, overlapping adsorption and desorption isotherm curves with no hysteresis",Virtually all MOFs can withstand heating in air to above 800 °C because their metal–ligand bonds are as strong as those in inorganic oxides,B,Materials,Easy,Basic,MOF Synthesis Q&A