9 ethylguanine

2-Phenylpyridine, 4-pyridinemethanol, 4-dimethylaminopyridine,
methylnicotinate, N,N-diethylnicotinamide, 3-picoline,
4-picoline, 3-acetylpyridine, 9-ethylguanine, and 9-methyladenine
were purchased from Sigma-Aldrich. For the biological experiments,
RPMI-1640 medium, fetal bovine serum, l-glutamine, penicillin/streptomycin
mixture, trypsin/EDTA, and phosphate-buffered saline (PBS) were purchased
from PAA Laboratories GmbH. Cisplatin CDDP (≥99.9%), trichloroacetic
acid (≥99%), sulforhodamine B (75%), sodium phosphate monobasic
monohydrate (≥99%), sodium phosphate dibasic heptahydrate (≥99%),
acetic acid (≥99%), staurosporine, propidium iodide (>94%),
and RNase A were obtained from Sigma-Aldrich. Complex [(η⁵-Cp^xph)Ir(phpy)Cl] was prepared according to reported
methods.^6d

IrCl₃·nH₂O (99%) was purchased
from Precious Metals Online (Australia).
1,2,3,4,5-Pentamethylcyclopentadiene, NaCl (>99.999%), tetrakis(triphenylphosphine)palladium
(99%), phenylboronic acid, 6-bromo-3-pyridinecarboxaldehyde,
2-bromo-4-nitropyridine, 4-formylphenylboronic acid, 4-(hydroxymethyl)phenylboronic
acid, 4-hydroxyphenylboronic acid, 2-bromo-4-hydroxymethylpyridine,
2-bromo-4-methylpyridine, 2-bromo-5-fluoropyridine (97%), p-tolylboronic acid (97%), 4-nitrophenylboronic acid (95%),
9-ethylguanine (≥98%), 9-methyladenine (97%), and β-nicotinamide
adenine dinucleotide-reduced dipotassium salt (≥95%) were purchased
from Sigma-Aldrich (UK). 2-Bromopyridine, 2-fluorophenylboronic acid,
and 4-fluorophenylboronic acid were purchased from Fisher Scientific
(UK), 2-bromo-5-hydroxypyridine and 2-bromo-5-methylpyridine were
from VWR International Ltd. (UK), and 2-bromo-3-fluoropyridine was
from Tokyo Chemical Industry Ltd. (UK). Solvents used for synthesis
were of laboratory grade and used without further purification. Solvents
for RP-HPLC (water and acetonitrile) were of HPLC grade with added
trifluoroacetic acid (purchased from Sigma-Aldrich (UK)) for purity
measurements. [(η⁵-Cp*)IrCl₂]₂ was synthesized according to a literature procedure.³⁶