## 3 Results and Discussion
### Solid State Structural Features: X-ray Crystallography
\begin{table}
\begin{tabular}{l l l} \hline Compound & **3d** & **4c** \\ Formula & C\({}_{12}\)H\({}_{7}\)F\({}_{3}\)O\({}_{2}\) & C\({}_{12}\)H\({}_{6}\)F\({}_{3}\)O\({}_{2}\) \\ Formula Weight (\(g/mol\)) & 240.18 & 242.19 \\ crystal size (\(mm\)) & 0.46 \(\times\) 0.08 \(\times\) 0.04 & 0.38 \(\times\) 0.28 \(\times\) 0.04 \\ crystal color/shape & orange yellow needle & colourless plate \\ cryst syst & orthorhombic & triclinic \\ space group & P n a 2\({}_{1}\) & P-1 \\ temp, K & 110 & 110 \\ \(a\), Å & 13.5923(5) & 7.3528(2) \\ \(b\), Å & 14.9695(5) & 7.9165(2) \\ \(c\), Å & 4.8381(2) & 9.7991(2) \\ \(a\),\({}^{\circ}\) & 90.00 & 73.0533(11) \\ \(\beta\),\({}^{\circ}\) & 90.00 & 85.3968(12) \\ \(\gamma\),\({}^{\circ}\) & 90.00 & 68.3581(11) \\ V, Å\({}^{3}\) & 984.41(6) & 506.92(2) \\ Reflections to final unit cell & 5859 & 6416 \\ 2\(\theta\) range, \({}^{\circ}\) & 5.44–52.66 & 5.78–71.38 \\ Z & 4 & 2 \\ F(000) & 488 & 248 \\ \(\rho\) (\(g/cm\)) & 1.621 & 1.587 \\ \(\lambda\), Å, (MoK\(\alpha\)) & 0.71070 & 0.71073 \\ \(\mu\), (\(cm^{-1}\)) & 0.147 & 0.143 \\ Reflections collected & 21568 & 20479 \\ Unique reflections & 2632 & 4691 \\ R\({}_{\rm merge}\) & 0.0444 & 0.0265 \\ Cut off Threshold Expression & \(>\)2 sigma(I) & \(>\)2 sigma(I) \\ refinement method & full matrix least-sqs using F\({}^{2}\) & full matrix least-sqs using F\({}^{2}\) \\ Weighting Scheme & 1/[sigma\({}^{2}\) (Fo\({}^{2}\)) + (0.0406P)\({}^{2}\) + 1/[sigma\({}^{2}\) (Fo\({}^{2}\)) + (0.0707P)\({}^{2}\) + 0.0000P] where P = (Fo\({}^{2}\) + 2 Fc\({}^{2}\))/3 \\ P = (Fo\({}^{2}\) + 2 Fc\({}^{2}\))/3 \\ R\({}_{1}\)\({}^{\rm a}\) & 0.0370 & 0.0382 \\ wR\({}_{2}\) & 0.0712 & 0.1082 \\ \hline \end{tabular}
\end{table} 
Table 2: Crystal data and structure refinement for **3d** and **4c**. In the case of compound **1d**, the small O\({}_{3}\)-C\({}_{10}\)-C\({}_{18}\)-C\({}_{3}\) dihedral angle of \(-2.4^{\circ}\) shows bindone to be nearly planar across the ring bridge in the solid state. The C-O and C\({}_{3}\)-C\({}_{10}\) bond lengths are consistent with those of typical carbonyls and alkenes, respectively and identify **1d** as a cross-conjugated triketone in the solid state. For **2c**, x-ray crystallography confirms the preference of a previously unreported structure in the solid state: a planar, exocyclic dienol shown in Figure 4. The weak intramolecular H-bonding normally observed in cyclic triketones is clearly supported for **2c** by the interatomic O'\(\cdots\)H-O distances of 1.75A and 1.81A and very short O-H bond lengths of 0.88A and 0.90A [11, 22]. The small O\({}_{1}\)-C\({}_{1}\)-C\({}_{2}\)-C\({}_{10}\) dihedral angle of \(-1.91^{\circ}\) attests to the planar nature of the cyclopentanone residue. Likewise, 3-trifluoroacetyl-2-naphthhol (**3d**) and 2-trifluoroacetyl-1-tetralone (**4c**) show trends consistent with a single endocytic cis-enol tautomer having weak intramolecular H-bonding, e.g., \begin{table}
\begin{tabular}{l l l} \hline Compound & **3d** & **4c** \\ R\({}_{1}\) (all data)\({}^{\mathrm{b}}\) & 0.0538 & 0.0525 \\ wR\({}_{2}\) (all data)\({}^{\mathrm{a}}\) & 0.0762 & 0.1220 \\ GOF & 1.035 & 1.048 \\ \hline \end{tabular} \({}^{\mathrm{a}}\) R\({}_{1}\) = \(\mathcal{I}\)[F\({}_{\mathrm{o}}\) - F\({}_{\mathrm{c}}\)]/\(\mathcal{I}\) F\({}_{\mathrm{o}}\), wR\({}_{2}\) = [\(\mathcal{I}\)w(F\({}_{\mathrm{o}}\) - F\({}_{\mathrm{c}}\))\({}^{2}\)]/\(\mathcal{I}\)[F\({}_{\mathrm{o}}\) - \(\mathrm{F}_{\mathrm{c}}\)]\({}^{2}\)]/(No. refIns. – No. params.)]\({}^{\mathrm{f}}\)\({}^{\mathrm{a}}\);  
\({}^{\mathrm{b}}\) R\({}_{1}\) = \(\mathcal{I}\)[F\({}_{\mathrm{c}}\)]/\(\mathcal{I}\) F\({}_{\mathrm{o}}\), wR\({}_{2}\) = [\(\mathcal{I}\)w(F\({}_{\mathrm{o}}\) - F\({}_{\mathrm{c}}\))\({}^{2}\)]/\(\mathcal{I}\)[wF\({}_{\mathrm{o}}\) + \(\mathcal{I}\)]/\(\mathcal{I}\), GOF = [\(\mathcal{I}\)[w(F\({}_{\mathrm{o}}\) - F\({}_{\mathrm{c}}\))\({}^{2}\)]/(No. refIns. – No. params.)]\({}^{\mathrm{f}}\)\({}^{\mathrm{a}}\)  
\end{table}