«ISSN 2078-5615. ³ñíèê Ëüâ³âñüêîãî óí³âåðñèòåòó. Ñåð³ÿ õ³ì³÷íà. 2013. Âèïóñê 54. ×. 2. Ñ. 377– Visnyk of the Lviv University. Series Chemistry. 2013. Issue 54. Pt. 2. P. 377–382 ÓÄÊ ...»
ISSN 2078-5615. ³ñíèê Ëüâ³âñüêîãî óí³âåðñèòåòó. Ñåð³ÿ õ³ì³÷íà. 2013. Âèïóñê 54. ×. 2. Ñ. 377–
Visnyk of the Lviv University. Series Chemistry. 2013. Issue 54. Pt. 2. P. 377–382
ÓÄÊ 544.18;546.57;547.569
ÁÓÄÎÂÀ ÒÀ ÅËÅÊÒÐÎÍͲ ÂËÀÑÒÈÂÎÑÒ² ÌÎËÅÊÓË
ÌÅÐÊÀÏÒÎÀͲ˲Ͳ ÒÀ ¯ÕÍ²Õ ÑвÁÍÈÕ ÑÎËÅÉ
Â. Äóòêà, ². Ñàìñîíîâà, Í. Äàâèäåíêî
Ëüâ³âñüêèé íàö³îíàëüíèé óí³âåðñèòåò ³ìåí³ ²âàíà Ôðàíêà,
âóë. Êèðèëà ³ Ìåôîä³ÿ, 6, 79005 Ëüâ³â, Óêðà¿íà
e-mail: vdutka@ukr.net Íàï³âåìï³ðè÷íèì êâàíòîâî-õ³ì³÷íèì ìåòîäîì ÐÌ6 ðîçðàõîâàíî ì³æ’ÿäåðí³ â³ääàë³, òåïëîòè óòâîðåííÿ, äèïîëüí³ ìîìåíòè, îá’ºìè òà ïëîù³ ìîëåêóë ìåðêàïòîàí³ë³í³â ³ ¿õí³õ ñð³áíèõ ñîëåé. Áóäîâà äîñë³äæóâàíèõ ìåðêàïòîàí³ë³í³â – áëèçüêà. Àì³íîãðóïà òà áåíçåíîâå ê³ëüöå ëåæàòü â îäí³é ïëîùèí³. Íà ï³äñòàâ³ âèêîíàíèõ ðîçðàõóíê³â ìîæíà ïðîãíîçóâàòè, ùî êóò, ï³ä ÿêèì îð³ºíòóâàòèìóòüñÿ ìîëåêóëè ìåðêàïòîàí³ë³í³â ó ñàìîîðãàí³çîâàíèõ øàðàõ ó ðàç³ ìîäèô³êàö³¿ ïîâåðõí³ ñð³áëà, áóäå áëèçüêo 90î. Ðîçðàõîâàíî òåïëîâ³ åôåêòè ïðîöåñ³â ìîäèô³êàö³¿ ïîâåðõí³ ñð³áëà.
Êëþ÷îâ³ ñëîâà: êâàíòîâî-õ³ì³÷í³ ðîçðàõóíêè, ìåðêàïòîàí³ë³í, ñð³áëî, ãåîìåòðè÷íà ñòðóêòóðà, åëåêòðîííà ñòðóêòóðà, òåïëîòè ðåàêö³¿.
Ìåðêàïòîàí³ë³íè ìîæíà óñï³øíî âèêîðèñòîâóâàòè äëÿ ìîäèô³êàö³¿ ïîâåðõí³ áëàãîðîäíèõ ìåòàë³â [1, 2]. Ó õîä³ ðåàêö³¿ ìåðêàïòîàí³ë³í³â ç ÷àñòèíêàìè çîëîòà, ñð³áëà òà ³íøèìè ìîæíà îòðèìàòè ñàìîîðãàí³çîâàí³ øàðè (ÑÎØ) íà ¿õí³é ïîâåðõí³.
Äîñë³äæåííÿì ô³çèêî-õ³ì³÷íèõ âëàñòèâîñòåé ÑÎØ ïðèñâÿ÷åíî áàãàòî ïðàöü [3–6].
Á³ëüø³ñòü ïðàöü ç âèâ÷åííÿ ÑÎØ ñòîñóþòüñÿ äîñë³äæåííÿ åëåêòðîõ³ì³÷íî¿ ïîâåä³íêè åëåêòðîä³â, ìîäèô³êîâàíèõ ò³îñïîëóêàìè, òîä³ ÿê îñîáëèâîñòÿì ôîðìóâàííÿ ÑÎØ ïðèä³ëåíî çíà÷íî ìåíøå óâàãè. Âïëèâó ñòðóêòóðè ìåðêàïòîàí³ë³í³â íà ôîðìóâàííÿ òà ô³çèêî-õ³ì³÷í³ âëàñòèâîñò³ ÑÎØ òàêîæ íå äîñë³äæóâàëè. Òîìó íàøà ìåòà – òåîðåòè÷íî äîñë³äèòè êâàíòîâî-õ³ì³÷íèìè ìåòîäàìè ñòðóêòóðó òà åëåêòðîíí³ âëàñòèâîñò³ ìåðêàïòîàí³ë³í³â ³ ¿õí³õ ñð³áíèõ ñîëåé.
Ðåçóëüòàòè òàêîãî äîñë³äæåííÿ áóäóòü êîðèñíèìè äëÿ ïðîãíîçóâàííÿ ñòðóêòóðè ÑÎØ ³ ô³çèêî-õ³ì³÷íèõ âëàñòèâîñòåé ìåðêàïòîàí³ë³í³â, çâ’ÿçàíèõ ç³ ñð³áëîì.
Êâàíòîâî-õ³ì³÷í³ ðîçðàõóíêè âèêîíóâàëè íàï³âåìï³ðè÷íèì ìåòîäîì ÐÌ6 ç ïàêåòà ïðîãðàì WINMOPAC 2009 ³ç âèêîðèñòàííÿì ãðàô³÷íîãî ³íòåðôåéñó Winmostar. Íàï³âåìï³ðè÷íèé ìåòîä êâàíòîâî-õ³ì³÷íîãî ðîçðàõóíêó ÐÌ6 äຠçìîãó, íà â³äì³íó â³ä ³íøèõ ìåòîä³â, äîñë³äæóâàòè ìîëåêóëè, ÿê³ ì³ñòÿòü êð³ì àòîì³â (Ñ, Î, Í), ³íø³ âàæê³ àòîìè (N, S, Ag). Òîìó öåé ìåòîä íàéë³ïøèé äëÿ íàøèõ ñïîëóê. Ìè âèêîíóâàëè ðîçðàõóíêè äëÿ 2-ìåðêàïòîíà³ë³íó (2-ÌÀí), 3-ìåðêàïòîàí³ë³íó (3-ÌÀí), 4-ìåðêàïòîàí³ë³íó (4-ÌÀí) òà ¿õí³õ ñð³áíèõ ñîëåé (2-ÌAíAg, 3-ÌAíAg, 4-ÌAíAg, â³äïîâ³äíî).
×èñëîâ³ çíà÷åííÿ òåïëîò óòâîðåííÿÍ f298, êÄæ/ìîëü), ïîòåíö³àë³â ³îí³çàö³¿ ( (²õ), äèïîëüíèõ ìîìåíò³â (D), åíåðã³é âèùî¿ çàéíÿòî¿ (ÂÇÌÎ) òà íèæ÷î¿ âàêàíòíî¿ (ÍÂÌÎ) ìîëåêóëÿðíèõ îðá³òàëåé, ïëîù (S, 2) òà îá’ºìó (V, 3) ìîëåêóëè íàâåäåí³ â òàáë. 1. Çà åíåð㳺þ ÂÇÌÎ òà ÍÂÌÎ ðîçðàõóâàëè åëåêòðîííèé õ³ì³÷íèé ïîòåíö³àë ___________________
© Äóòêà Â., Ñàìñîíîâà ²., Äàâèäåíêî Í., 2013 Â. Äóòêà, ². Ñàìñîíîâà, Í. Äàâèäåíêî ISSN 2078-5615. ³ñíèê Ëüâ³âñüêîãî óí³âåðñèòåòó. Ñåð³ÿ õ³ì³÷íà. 2013. Âèïóñê 54. ×. 2 () ìîëåêóë ³ æîðñòê³ñòü ìîëåêóëè ( ) çà ôîðìóëàìè = (ÅÂÇÌÎ + ÅÍÂÌÎ )/2 òà = (ÅÍÂÌÎ – ÅÂÇÌÎ) [7,8].
Íàãîëîñèìî, ùî ðîçðàõîâàíå çíà÷åííÿ äèïîëüíîãî ìîìåíòó äëÿ 2-ÌÀí äîð³âíþº 1,71 (äèâ. òàáë. 1) äîáðå çá³ãàºòüñÿ ç³ çíàéäåíèì åêñïåðèìåíòàëüíî, ÿêå ñòàíîâèòü 1,69 [9]. Ó ë³òåðàòóð³ íåìà åêñïåðèìåíòàëüíèõ ðåçóëüòàò³â òåïëîò óòâîðåííÿ ³ äèïîëüíèõ ìîìåíò³â äîñë³äæóâàíèõ ðå÷îâèí, òîìó ðîçðàõîâàí³ òåîðåòè÷íî çíà÷åííÿ ìîæóòü áóòè êîðèñíèìè äëÿ ðîçðàõóíê³â çì³íè òåðìîäèíàì³÷íèõ ïàðàìåòð³â ó õîä³ ôîðìóâàííÿ ÑÎØ. ×èñëîâ³ çíà÷åííÿ Í f298 äëÿ âèõ³äíèõ ìåðêàïòîò³îàí³ë³í³â áëèçüê³ ³ º â ìåæàõ 84,50–93,12 êÄæ/ìîëü. Çàì³ùåííÿ àòîìà ã³äðîãåíó íà àòîì ñð³áëà ïðèâîäèòü äî ñóòòºâîãî çðîñòàííÿ Í f298 (äèâ. òàáë. 1). Åíåðã³ÿ ÂÇÌÎ äëÿ âñ³õ ìåðêàïòîàí³ë³í³â ïðàêòè÷íî îäíàêîâà ³ º â ìåæàõ â³ä -7,961 äî -8,643 åÂ. Çàì³íà àòîìà âîäíþ ó ñóëüôã³äðèëüí³é ãðóï³ ìåðêàïòîàí³ë³í³â íà àòîì ñð³áëà íå çì³íþº åíåð㳿 ÂÇÌÎ, ÿêà äîð³âíþº â³ä -8,538 äî -8,795 åÂ. Åíåðã³ÿ ÍÂÌÎ äëÿ âèõ³äíèõ ñïîëóê çì³íþºòüñÿ á³ëüøå â³ä 0,218 äî -0,033 åÂ. ×èñëîâ³ çíà÷åííÿ åíåð㳿 ÍÂÌÎ çíà÷íî çìåíøóþòüñÿ äëÿ ñð³áíèõ ñîëåé ìåðêàïòîàí³ë³í³â ³ º â ìåæàõ â³ä 3,403 äî 3,675 åÂ.
Ìåòîä ãðàíè÷íèõ îðá³òàëåé, çàïðîïîíîâàíèé Ôóêó¿, âèçíà÷ຠâ³äíîñíó ðåàêö³éíó àêòèâí³ñòü ñïîëóê çà åíåð㳺þ ìîëåêóëÿðíèõ îðá³òàëåé ÂÇÌÎ òà ÅÂÇÌÎ çóìîâëþº âçàºìîä³þ ìîëåêóëè ç ÍÂÌÎ [10, 11].
Â. Äóòêà, ². Ñàìñîíîâà, Í. Äàâèäåíêî ISSN 2078-5615. ³ñíèê Ëüâ³âñüêîãî óí³âåðñèòåòó. Ñåð³ÿ õ³ì³÷íà. 2013. Âèïóñê 54. ×. 2 379
Çàì³íà àòîìà ã³äðîãåíó íà àòîìè ñð³áëà â ìîëåêóëàõ äîñë³äæóâàíèõ ñïîëóê ïðèâîäèòü äî ñóòòºâîãî çðîñòàííÿ äîâæèíè çâ’ÿçêó S-Ag ç 2,371 äî 2,462 (äèâ. òàáë. 2).
Ãðóïà NH2 ëåæèòü â îäí³é ïëîùèí³ ç áåíçåíîâèì ê³ëüöåì, ïðè ÷îìó êóò Í-N-H äîð³âíþº ~120î. Ïëîñêèé êóò ì³æ àòîìàìè C(6)S(8)Ag(9) â ïîð³âíÿíí³ ç ïîä³áíèì êóòîì C(6)S(8)H(9) çìåíøóºòüñÿ â³ä 120,0–122,6î äî 93,1–98,8î (äèâ. òàáë. 2). Öÿ îñîáëèâ³ñòü äຠçìîãó ïðîãíîçóâàòè êóò, ï³ä ÿêèì áóäóòü îð³ºíòîâàí³ ìîëåêóëè ìåðêàïòîàí³ë³í³â ó ðàç³ âçàºìî䳿 ¿õ ç ïîâåðõíåþ ìåòàëåâîãî ñð³áëà. ×èñëîâ³ çíà÷åííÿ öüîãî êóòà çàëåæàòü â³ä áóäîâè ìåðêàïòîàí³ë³íó º â ìåæàõ 93,1–98,8î (äèâ. òàáë. 2).
Ðîçðàõóíêè ÷àñòêîâèõ çàðÿä³â íà àòîìàõ äîñë³äæóâàíèõ ìåðêàïòîàí³ë³í³â òà ¿õí³õ ñð³áíèõ ñîëåé íàâåäåí³ â òàáë. 3. Îòðèìàí³ ðåçóëüòàòè ï³äòâåðäæóþòü âèñíîâêè ïðî âèñîêó ðåàêö³éíó çäàòí³ñòü äîñë³äæóâàíèõ ñïîëóê.
×àñòêîâèé çàðÿä íà àòîì³ N(7) çðîñòຠâ³ä -0,554 äî -0,504 â ðàç³ çàì³íè àòîìà ã³äðîãåíó â ñóëüôã³äðèëüí³é ãðóï³ íà àòîì ñð³áëà, òîä³ ÿê äëÿ àòîìà S(8) ïðîñòåæåíî çâîðîòíèé åôåêò (äèâ. òàáë. 3). Àòîìè êàðáîíó Ñ(1) òà Ñ(5) ìàþòü íåâèñîê³ çíà÷åííÿ ÷àñòêîâèõ çàðÿä³â íà àòîìàõ. ×àñòêîâ³ çàðÿäè íà àòîìàõ êàðáîíó Ñ(2) òà Ñ(4) – âèñîê³ é ïðàêòè÷íî îäíàêîâ³ ÿê äëÿ âèõ³äíèõ ìåðêàïòîàí³ë³í³â, òàê ³ äëÿ ¿õí³õ ñð³áíèõ ñîëåé.
Â. Äóòêà, ². Ñàìñîíîâà, Í. Äàâèäåíêî ISSN 2078-5615. ³ñíèê Ëüâ³âñüêîãî óí³âåðñèòåòó. Ñåð³ÿ õ³ì³÷íà. 2013. Âèïóñê 54. ×. 2
Ðåçóëüòàòè, íàâåäåí³ â òàáë. 3, ñâ³ä÷àòü, ùî áåíçåíîâå ê³ëüöå ì³ñòèòü öåíòðè, íà ÿê³ ìîæëèâà ÿê åëåêòðîô³ëüíà, òàê ³ íóêëåîô³ëüíà àòàêà. Äëÿ àòîìà êàðáîíó Ñ(3), çâ’ÿçàíîãî ç àòîìîì í³òðîãåíó, õàðàêòåðíèé äåô³öèò åëåêòðîííî¿ ãóñòèíè, ÿêà ñòàíîâèòü 0,287 – 0,359 ³ íå çàëåæèòü â³ä òèïó àòîìà, çâ’ÿçàíîãî ç àòîìîì ñóëüôóðó.
Âçàºìîä³ÿ ìåðêàïòîàí³ë³í³â ç àòîìàìè ñð³áëà íà ïîâåðõí³ â³äáóâàºòüñÿ çà ñõåìîþ
Îòæå, íà ï³äñòàâ³ âèêîíàíèõ êâàíòîâî-õ³ì³÷íèõ ðîçðàõóíê³â ìîæíà âèâ÷àòè ðåàêö³éíó çäàòí³ñòü, ñòðóêòóðó òà ïðîãíîçóâàòè îñîáëèâîñò³ âçàºìî䳿 ñð³áëà ç ìåðêàïòîàí³ë³íàìè.
Â. Äóòêà, ². Ñàìñîíîâà, Í. Äàâèäåíêî ISSN 2078-5615. ³ñíèê Ëüâ³âñüêîãî óí³âåðñèòåòó. Ñåð³ÿ õ³ì³÷íà. 2013. Âèïóñê 54. ×. 2 381 ________________________________
Âîëêîâ Ñ.À., Êîâàëü÷óê ª.Ï., Îãåíêî Â.Ì. òà ³í. Íàíîõ³ì³ÿ. Íàíîñèñòåìè.
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Êóïèòü ñàæåíöû è ÷åðåíêè âèíîãðàäà |
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MERCAPTOANILINE MOLECULES AND THEIR SILVER SALTS STRUCTURE
AND ELECTRONIC PROPERTIES
The internuclear distances, the heat of formations, the dipole moments, the mercaptoaniline molecules and their silver salts volumes and areas have been calculated by semiempirical quantumchemical method PM6. It was found that the structure of mercaptoaniline molecules is similar. An amino-group and a benzene ring are in one plane. Based on performed calculations it is possible to predict that after the surface modification the mercaptoaniline molecules in the SAM are oriented almost perpendicular to the silver surface. The heat of formation for the process of the silver surface modification was found.
Ïîëóýìïèðè÷åñêèì êâàíòîâî-õèìè÷åñêèì ìåòîäîì ÐÌ6 ðàññ÷èòàíî ìåæúÿäåðíûå ðàññòîÿíèÿ, òåïëîòû îáðàçîâàíèÿ, äèïîëüíûå ìîìåíòû, îáúåìû è ïëîùàäè ìîëåêóë ìåðêàïòîàíèëèíîâ è èõ ñåðåáðÿíûõ ñîëåé. Ñòðîåíèå èçó÷åííûõ ìåðêàïòîàíèëèíîâ áëèçêî.
Àìèíîãðóïïà è áåíçîëüíîå êîëüöî ëåæàò â îäíîé ïëîñêîñòè. Íà îñíîâàíèè ïðîâåäåííûõ ðàñ÷åòîâ ìîæíî ïðîãíîçèðîâàòü, ÷òî óãîë, ïîä êàêèì áóäóò ðàñïîëîæåíû ìîëåêóëû ìåðêàïòîàíèëèíîâ â ÑÎØ, ïðè ìîäèôèêàöèè ïîâåðõíîñòè ñåðåáðà áëèçîê ê 90î. Ðàññ÷èòàíî òåïëîâûå ýôôåêòû ïðîöåññîâ ìîäèôèêàöèè ïîâåðõíîñòè ñåðåáðà.
Êëþ÷åâûå ñëîâà: êâàíòîâî-õèìè÷åñêèå ðàñ÷åòû, ìåðêàïòîàíèëèí, ñåðåáðî, ãåîìåòðè÷åñêàÿ ñòðóêòóðà, ýëåêòðîííàÿ ñòðóêòóðà.