ڈاکٹر تارا چند
گذشتہ اکتوبر میں ڈاکٹر تاراچند کے انتقال پر ملال سے بھی ہندوستان میں ایک بڑا علمی خلاء پیدا ہوگیا، وہ الہ آباد کے کایستھ پاٹ شالہ کی مدرسی اور پرنسپلی کے بعد الہ آباد یونیورسٹی کے وائس چانسلر بھی ہوئے، پھر حکومت ہند کے تعلیمی مشیر بنے، ایران میں ہندوستان کی طرف سے سفیر بناکر بھیجے گئے، وہاں سے واپسی پر پارلیمنٹ کے رکن نامزد کئے گئے لیکن ان کی اصلی شہرت اور مقبولیت ایک بلند پایہ مورخ کی حیثیت سے ہوئی، انھوں نے ’’انفلوانس آف اسلام ان انڈین کلچر‘‘ پر ایک مقالہ لکھ کر آکسفورڈ سے ڈاکٹریٹ کی ڈگری حاصل کی، یہ ان کی ابتدائی تحقیقی کوشش تھی، لیکن اس سے بہتر کتاب اس موضوع پر اب تک نہیں نکلی، آخر میں وہ ہسٹری آف دی فریڈم موومنٹ کے بورڈ کے اڈیٹر تھے، ان کی ادارت میں یہ کام بڑی خوش اسلوبی سے انجام پاتا رہا، ان کی تحقیقی تحریروں میں دیدہ دری کے ساتھ بڑی فراخدلی بھی ہوتی، وہ ہندی اردو کی حسین آمیزش یعنی ہندوستانی زبان کے بھی بڑے موئد تھے، اس کے کچھ اچھے نمونے بھی لکھ کر پیش کرتے رہے، ان کی نیک نامی اور مورخانہ بصیرت کی وجہ سے ان کی خوشگوار یادوں کا چراغ علمی حلقہ میں برابر روشن رہے گا۔ (’’ص ، ع‘‘، نومبر ۱۹۷۳ء)
According to Hadith literature, the Quran is revealed in seven Ahruf, the plural of harf. Ahruf are distinct from Qira'at. This is a very momentous and lengthy topic, indeed, one of the most complicated discussions on the sciences of the Qur’an. It is very difficult to discuss it in full details in this work but the important things about it are being presented in this article. The first problem we face with this Hadith is what is meant by the Revelation of Qur’an on Seven “Ahruf”? We find a great deal of difference of opinion on this subject. Up to thirty five different views have been quoted by Ibn al-‘Arabi and others. Some of the popular views are quoted in this article. The context of these narrations indicates clearly that the word ‘seven’ does not denote an unspecified large number but it denotes the specific numerical value ‘seven’. Hence, in the light of these narrations this view (that seven means more than that) does not hold good and the majority of scholars reject it. In the vast collections of Hadiths, we do not find any mention of difference in the Qur’an other than that accounted for in “ahruf”. How then may we explain differences in reading and “ahruf”? I have not been able to find a satisfactory answer to this confusion with the advocates of this theory.
Bismuth and lead based MOFs (1–21) have been synthesized by using eight different organic linkers. For better understanding and comparison of structural and bonding aspects, these linkers were divided into four categories (A–D). This categorization was made on the basis of functional molecules present in them. Category A include linkers having only dicarboxylate groups i.e., (biphenyl-4,4′-dicarboxylic acid (H2BDA), 2,6-naphthalenedicarboxylic acid (2,6-NDA), 2,5-thiophenedicarboxylic acid (H2TDC), 2-bromoterephthalic acid (H2-BTA)),Category B include linker having dicarboxylate and hydroxyl groups i.e., (5-hydroxyisophthalic acid (H2HIA)), Category C include linkers having monocarboxylate and thione groups i.e., (2-mercapto-3-methyl-4 thiazoleacetic acid (H2MMTA), 4-mercaptobenzoic acid (H2MBA)) and Category D include linker having thione and hydroxyl groups i.e., (4,6-dihydroxy-2-mercapto pyrimidine (H2-DMP)). MOFs (1–9) were synthesized from A linkers, MOFs (10–12) were synthesized from B linker. Similarly MOFs (13–18) were synthesized from C linkers and MOFs (19–21) were synthesized from D linker. The morphological and other structural aspects of all these MOFs (1–21) have been established on the basis of Fourier transform infrared spectroscopy (FTIR), 1H NMR, Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), Thermogravimetric analysis (TGA), Powder X-ray diffraction techniques and in case of MOF (13) single-crystal X-ray diffraction have been used. MOF (13) exhibited orthorhombic crystal system in which central lead metal ions form a chain which is bridged to other chains through H2MMT linker to form a 3D framework. The octahedron around each lead was hemidirected. Powder XRD revealed orthorhombic system for MOFs (2, 4–13, 15 & 18–21), trigonal xx crystal system for MOF (3), hexagonal crystal system for MOF (12) and monoclinic crystal system for MOFs (16 & 17). Thermogravimetric analysis was carried out to investigate the thermal stability of all MOFs (1–21). It was observed that all bismuth MOFs (3, 5, 15 & 18) are relatively more stable than lead based MOFs (1–4, 6–11, 13, 14, 16, 17–20). All these MOFs exhibited appreciable to good luminescence activity. Lead-based MOFs exhibited better emission at 527 nm, 499 nm and 514 nm among all other MOFs. Adsorption behavior is a key focus in MOFs application. Hence BET studies for MOFs (1–21) were investigated to estimate the surface area that is in the range 196-5316 m2/g. Among these MOFs, highest surface area was found to be3699 m2/g for (6), 2866.5 m2/g for (10), 3266.5 m2/g for (11), 5130 m2/g for (14), 5316 m2/g for (15), 2184m2/g for (18) and 3477 m2/g for (21) and showed appreciable to good adsorption capacity (17.62 mmol/g (6), 11.12 mmol/g (10), 6.23 mmol/g (11),9.12 mmol/g (14), 11.90 mmol/g (15), 1.84 mmol/g (18) and 13.66 mmol/g (21)) for N2. Bismuth is surprisingly less toxic relative to its neighboring elements (Pb & Tl). Therefore we have also investigated antibacterial activity of bismuth MOFs against three Gram-Positive (Staphylococcus aureus, Bacillus cereus and Clostridium and two Gram-negative bacteria (Escherichia coli and Enterobacter aerogenes). All bismuth MOFs exhibited appreciable to good inhibitory affects against these microorganisms than free linkers. Higher activity was observed against bacillus cereus compared to other strains. The increasing order of the activity for bismuth MOFs against bacillus cereus are MOFs (21)> MOF (18)> MOF (15)> MOF (3)> MOF (5)> MOF (12).